Lets see your history of ''tier'' of clearing

[inboundpaper]

1-9 didn't clear lol
10 cleared
11&12 didn't clear lol
13 cleared
14 probably not

Sad part is I started playing in like 2004.

[ringpriest]

Tier 0.5: Cleared (but not until BC. One of the funnest chains in the game)
Tier 1: Cleared in vanilla
Tier 2: Cleared in vanilla (got carried by a very competent guild)
Tier 2.5: Never did it
Tier 3: Didn't run classic Naxx
Tier 4: Cleared
Tier 5: Cleared
Tier 6: Cleared
Tier 7: Cleared (H)
Tier 8: Cleared (H)
Tier 9: Cleared (Didn't get Heroic Yogg until Cata)
Tier 10: Cleared (everything but H LK)
Tier 11: Took a break
Tier 12: Cleared
Tier 13: Cleared 1st month it was out
Tier 14: Don't Play Anymore

[Rheckameohs]

Tiers 0.5 through 4: I was unable to raid during this time due to being inexperienced and lacking a solid guild.

Tier 5: Found a solid guild and cleared it completely just before SWP dropped.

Tier 6: We conquered Black Temple, but never set foot in SWP.

Tier 7-10: Absolutely, positively dominated. We even managed to complete all of the 10M Ulduar Hardmodes as well as Glory of the Icecrown Raider. I am proud of my Rusted Proto and my Vanquisher.

Tier 11: This one was a total bitch, but I loved it. Fuck you, Cho'Gal. I earned that kill.

Tier 12: Significantly more forgiving than Tier 11. Cleared with all achievements available in 10M normal and heroic.

Tier 13: Yawn. Cleared with relative ease.

Tier 14: We're off to an extremely slow start. We're currently 2/6 in 10M normal Mogu'shan Vaults and we haven't even touched Heart of Fear.

As you can tell, my guild runs exclusively 10 mans. 25 mans are great and all, but 10 mans encourage teamwork much more than the former in our opinion.

[Vyrd]

tier 0.5-3: didnt really raid a lot during vanilla. played my friends warrior in raids during vanilla though a few times. came back during TBC to do all vanilla content.
4. cleared
5. all but solarian and kaelthas
6. all but sunwell minus kalecgos
7. cleared
8. cleared
9. cleared
10. cleared
11. cleared
12. quit
13. raid finder clear
14. half of msv cleared. quit till 5.1

[Acry]

Tier 0.5 - T3: Didn't play
Tier 4: Cleared
Tier 5: Didn't kill Kael/Vashj till endo of BC nerf
Tier 6: Didn't kill Illidan till end of BC nerf, and none of sunwell
Tier 7: Cleared
Tier 8: Didn't play
Tier 9: Cleared
Tier 10: Didn't play
Tier 11: Cleared normal, heroic during DS
Tier 12: Cleared - Hrag, HRag during DS
Tier 13: Cleared ( HM )
Tier 14: 6/6 N 3/6 N atm

[Deleted]

Started playing in 3.3

Tier 10- 6/12 normal (till Rotface) and 2/12 HC
Tier 11- Half-year break
Tier 12- 5/7 normal
Another half-year break
Tier 13- 8/8 normal 1/8 HC
Tier 14- trying to get there.

[Amsden]

Tier 0.5: Cleared
Tier 1: Cleared
Tier 2: Cleared
Tier 2.5: Cleared
Tier 3: Spider wing only
Tier 4: Cleared
Tier 5: Cleared
Tier 6: everything but sunwell.
Tier 7: Cleared
Tier 8: Cleared
Tier 9: Cleared
Tier 10: Cleared
Tier 11: Cleared
Tier 12: On break (cleared with my guild on farm status though)
Tier 13: Cleared
Tier 14: MSV Cleared; HoF Still working on Garalon

[Xami]

Tier 0.5: Cleared
Tier 1: Cleared
Tier 2: Cleared
Tier 2.5: Cleared
Tier 3: Cleared all but Gothik, 4H, Sapph, K'T
Tier 4: Cleared
Tier 5: Cleared
Tier 6: Cleared
Tier 7: Didn't raid
Tier 8: Didn't raid
Tier 9: Didn't raid
Tier 10: Didn't raid
Tier 11: Cleared (Some heroic)
Tier 12: Cleared (Some heroic)
Tier 13: Cleared (heroic)
Tier 14: In Progress (1/6H + 2/6)

[a little Kappa]

Tier 0.5: Didnt play Pve
Tier 1: Didnt play Pve
Tier 2: Didnt play Pve
Tier 3: Didnt play PvE
Tier 4: Karazhan on rogue, gruul and magtheridon aswell.
Tier 5: Didnt raid much. Did some bosses in SSC
Tier 6: Nothing
Tier 7: Cleared
Tier 8: Cleared everything on 25 and 10 on rogue exept algalon and alone in the dark. Did one light though.
Tier 9: Everything on rogue exept Anub arak 25 hc. 0.08% wipe best try then ragequit PvE
Tier 10: Everything deaded exept LK 25 HC. Guild went 10 man with best players and killed him 10 man 1st night. (This was on hunter, switched back to rogue when he died 10 man)
Tier 11: 9/13 HC
Tier 12: 6/7 Hc prenerf, rag 25 HC prenerf 7% ish p4
Tier 13: 6/8 HC 25 man prenerf, spine 5% 25 man
Tier 14: 6/6 normal HoF 25, 4/6 HC MSV and currently progressing on RNG kings HC.

Yeah, I reroll a lot.

Edit: I did ZA too and ZG aswell. It was such a long time ago and I don't remember in which Tier they were.

[Rayr1fe]

Tier 0.5: Never raided
Tier 1: Never raided
Tier 2: Never raided
Tier 2.5: Never raided
Tier 3: Never raided
Tier 4: Cleared
Tier 5: Cleared
Tier 6: 5/5 MH, 1/9 BT 0/6 SW
Tier 7: Cleared
Tier 8: Cleared (HM)
Tier 9: Cleared (HM)
Tier 10: Cleared (HM)
Tier 11: Cleared (HM)
Tier 12: Cleared (HM)
Tier 13: Cleared (HM)
Tier 14: Never raided / LFR

[Deleted]

Played in TBC but never set foot in a raid. So nothing until..

Tier 7: Cleared with Naxx Undying and most achieves.
Tier 8: Cleared normal, all hard modes except Algalon and YoggHM. Got the meta drake + champion title.
Tier 9: Cleared ( HM ) including the wolf mount thingy.
Tier 10: Cleared ( HM ) on 10 man including the meta-drake. Normal on 25 man.
Tier 11: Cleared Normal, 4/6 bwd hc, 3/5 bot hc.
Tier 12: Cleared Normal, 6/7 heroic before DS released.
Tier 13: Cleared Normal on the first reset. 6/8 HC and retired from raiding before the nerfs/buff stacked up enough for us to get spine. Never returned to raiding.
Tier 14: Never raided.

[Arbs]

40Man:
Tier 1: Cleared - Oh how i love MC
Tier 2: Cleared - Nefarian, Onyxia oh how I miss raids that you got like a truck with minimal health even as a Tank
Tier 2.5: Cleared - AQ 40 was a great experience to bad I never got to kill C'thun until Tier 3 was already out
Tier 3: Plague, Construct & Arachnid Quaters w/ Miltary up to Four Horsemen
25Man:
Tier 4: Cleared - Love Kara to bad it was only 10 man
Tier 5: Cleared - Kael'thas & Lady Vashj were a pain in the ass
Tier 6: Cleared - Didn't down M'uru & KJ until after 3.0 nerfs
Tier 7: Cleared - Realm 2nd (Undermine PvE)
Tier 8: Cleared ( HM ) - Yogg 0 completed 2 weeks before ToC
Tier 9: Cleared ( HM - Grand Crusader on both 10 / 25 Man
Tier 10: Cleared ( HM ) Including Herioc Halion
Tier 11: Cleared ( HM ) - Everything except Sinestra until Tier 12 was on PTR than I killed Sinestra
Tier 12: Cleared ( HM ) - H Rag Post 1st Nerf
Tier 13: Cleared ( HM ) - DS 10% Debuff
Tier 14: Cleared (NM) (HM MSV 6/6) (2/6 HM HoF)

[monkfish]

Tier 0.5: Cleared
Tier 1: Cleared
Tier 2: Cleared
Tier 2.5: Only did aq40 upto Huhuran
Tier 3: No kills in Naxx40
Tier 4: Cleared
Tier 5: Cleared
Tier 6: Cleared although did M'uru and Kil'jaeden after 3.0 nerfs
Tier 7: Cleared inc os3d in 10 and 25
Tier 8: All but Mimiron HM/Yogg+1(and 0)/Algalon 25, Cleared all on 10(and hm's) + meta glory mount
Tier 9: All but abub25hc, Cleared all on 10 (insanity)
Tier 10: All but Lk25hc, Cleared all on 10 (lk hc on 10% buff) + glory mounts on 10 and 25
Tier 11: 8/13 heroic, never actually tried sinestra since either
Tier 12: 7/7 hc in 10man, 6/7 hc 25man + glory mount
Tier 13: 8/8 hc 25man
Tier 14: MSV Cleared, 1/6 in HoF (so far) [normal modes only atm, took a break from wow, only started raiding 2 weeks ago.. progress /on]

All while current content

[Deleted]

cleared everything but tier 3 and tier 11 and late tier 6 (swp) while it was still somewhat relevant (only cleared normal msv in tier 14 though, not raiding much in mop D

, still managed to kill atleast some bosses in these raids part from tier 3, during the time I was inactive.

[Deshi]

Tier 0.5: None
Tier 1: None
Tier 2: None
Tier 2.5: None
Tier 3: None
Tier 4:None
Tier 5: None
Tier 6: None
Tier 7: Cleared
Tier 8: Cleared ( HM )
Tier 9: Cleared ( HM
Tier 10: Cleared (some HM )
Tier 11: Cleared (some HM )
Tier 12: Cleared (some HM )
Tier 13: Cleared ( HM )
Tier 14: Progressing

[Xarganthos]

Tier 0.5: never played
Tier 1: never played
Tier 2: never played
Tier 2.5: never played
Tier 3: never played
Tier 4: Cleared
Tier 5: 2 Bosses
Tier 6: Never raided
Tier 7: Cleared
Tier 8: Cleared (many HMs included)
Tier 9: Cleared ( 4/5 HC )
Tier 10: Cleared ( 11/12 HC )
Tier 11: Cleared ( HC )
Tier 12: Cleared ( HC )
Tier 13: Cleared ( HC )
Tier 14: Current: Cleared ( Mogu'shan 3/6 HC )

[Chonar]

Since classic, absolutely everything... except Halion HC, if you wanna count him into Tier10.

We were hit with such a huge wall of CBA, you wouldn't believe.

Tier14 in progress, of course.

[Deleted]

Tier 0.5: Cleared
Tier 1: Cleared -
Tier 2: Never tried
Tier 2.5: Only AQ20 if that counts
Tier 3: Never tried
Tier 4: Cleared
Tier 5: Very few bosses
Tier 6: Never tried
Tier 7: Cleared
Tier 8: Cleared+HM
Tier 9: Cleared+HM
Tier 10: Cleared
Tier 11: Cleared
Tier 12: Cleared
Tier 13: Cleared+few HCs
Tier 14: About half way cleared

[Tekloth]

Tier 0.5: Cleared
Tier 1: Cleared
Tier 2: Cleared
Tier 2.5: Cleared ( Viscidus at lvl 80 )
Tier 3: Cleared PRE patch 2.0 (6min before server shutdown for patch, world #50)
Tier 4: Cleared
Tier 5: Cleared
Tier 6: Cleared
Tier 7: Cleared
Tier 8: Cleared ( HM )
Tier 9: Cleared ( HM )
Tier 10: Cleared ( 9/12 HM while content was relevant, quit raiding for a while here due to military) Minus Halion, the only boss I've never killed thus far, even when you take into account every world boss that has been available.
Tier 11: Didn't raid that much due to military, cleared at T12, HM cleared at T13 (not with main though)
Tier 12: Cleared ( HM )
Tier 13: Cleared ( HM )
Tier 14: 6/6 MsV N 3/6 HoF N

[Deleted]

Tier 1-11: Never raided when it was current.
Tier 12: Normal mode clear.
Tier 13: Cleared HC mode.
Tier 14: 6/6 MSV normal and 1/6 Heart of Fear.
Yeah, I'm a DS nab ^_^