Currently 15/16 (only done about 5 pulls on Sha of Fear), but so far my favorites have probably been Elegon overall. Was a very tense fight the entire time and was the greatest yells in achievement when we finally got him down. Also love the Attenuation mechanic on Imperial Vizier, felt like I was playing some retro space game where I had to dodge stuff flying at my ship. Honorable mention to Spirit Kings as well, just for how busy the fight is, very entertaining.
I really enjoyed Amber Shaper Un'sok , Four Kings, and Elegon. Those three would be my favourites, followed by Feng, Vizier, Wind Lord, Blade Lord and Lei Shi. Tier 14 has been a very good tier in my opinion, My second favourite since tier 8.
As a tank, I've enjoyed every fight I've seen thus far. Except Garalon. Garalon can go to hell. Feng is my favorite though, just because I get the Shroud of Reversal and can do so many little things with it.
MSV: Spirit Kings and Elegon were amazing fights. Heroic Spirit Kings was very enjoyable due to all the mchanics going on and it reminded me of Heroic Omnotron except for when we got Meng second then it just wasn't enjoyable. Elegon was a great fight on normal due to it being 3 phases, having a great environment and having some unique mechanics. I felt it should have been the end boss of MSV and buffed immensely on Heroic difficulty. They had so much potential with that fight on heroic.
HoF: Imperial Vizier and Amber Shaper. Heroic Imperial Vizier and attenuation is a marvelous mechanic. The entire fight was very well designed after they made it impossible for him to go left on the pull. Amber Shaper is a well designed "vehicle fight". To be able to kill it on Heroic you really need to execute the construct mechanic properly, while still handling the mechanics outside the construct as well. It's refreshing for a vehicle fight to do that since usually they make it so everything outside the vehicle is negligible. I used to enjoy Empress but after doing the boss on Heroic I realized how much I despise that fight. That kind of raid and tank damage is not enjoyable to heal and only encourages overpowered cooldown stacking (specifically disc priests/warriors).
Terrace: Tsulong is a great fight, giving equal importance to healing and dps. Protectors and Lei Shi just feel like something is missing in my opinion. Protectors should have had more awareness/dodge mechanics while Lei Shi should have had a 2nd phase, especially considering he is the penultimate boss of the tier. No input yet on Heroic Sha, but I don't think i'll enjoy it since its an endurance fight and those are the worst to wipe on.
I haven't done any heroics yet, but I like Tsulong a lot as a healer. I think Feng is kinda cool. New, unique mechanics without feeling gimmicky. Gara'jal is fun, the first guy in Heart of Fear is fun. Actually I like most of HoF. Elegon was challenging, and I like that aspect, but I didn't find the fight itself especially exciting.
Surprisingly, this might be the first tier in a long time where there wasn't a fight I really, really loathed. Almost every tier ever has at least one I really dislike.
Heroic Spirit Kings is amazing, so many mechanics that we haven't seen in years (stop attacking, dispel boss, break bubbles, stun boss) all while dealing with the familiar "don't stand in bad stuff" makes it feel like Heroic Ragnaros with the uniqueness of the fight.
i have enjoyed this tier, but none of the bosses stand out to me as fantastic. i HATE garalon though. and i hate wind lord, but thats purely because as an aff lock the aoe phase is so damn boring. one button spam is not fun. i enjoy stone guard HC on 25 but not on 10man (10 you spend too long painting) favourite is probably spirit kings, elegon of IVZ