Retribution paladins are the most offensive healers.
Please dont link that garbage video. Seriously I dont know who is playing the hpally or why he sucks so bad (seriously? Stay of execution?) but I can drop a stationary player in less than half that time. If im rocking an offensive spec (aka shock glyph) I have gotten over 120k holy shocks in arenas on players consistently with all cds + trinkets up and holy prism isnt much less. Hell I've forced another pally to bubble in a hoj by myself. Pallys win for damage, even though HoW is still pretty strong it is on a 6 min cd.
Depends on what you mean by "offensive." Are we talking, able to do the most damage, has the most CC, has the best mix of both, etc. A good Disc Priest can do more damage than any other healer hands down. It's always been that way. I'd say Mistweaver Monks who use the Melee style healing passive a lot, will also put out a fair amount of damage. Druids are going to have the most CC, but barely more than a Shaman. Druids for whatever god awful reason can Bash out of bear now, so that, plus Cyclone, plus Roots, makes them CC heavy. However a good Shaman with Wind Shear can make or break a fight. Also, this expansion in particular, Pallies are doing a weird amount of damage. If they take HoJ and Repent, their CC is stupid good too.
WoW : Burning Blade (H)90 Warlock, 90 Shaman, 96+ Mage, 90 Death Knight, 86 Warrior, 90 Hunter, 85 Rogue, 80 Paladin, 76 Priest, 70 Druid, 26 Monk
From my personal experience as a healer id say disc priest, but seeing as i have not played a monk healer I can't really say either way on that .
A balance druid;P....
But Seriously it depends on what you need. For damage I would say either monk or paladin, depending on different situations. For offensive ccs I see druids and shamans taking that, shamans can purge,interrupt, and hex while druids can chain cc,bash and use hotw.
Time...line? Time isn't made out of lines. It is made out of circles. That is why clocks are round. ~ Caboose
Resto druid. Apparently they got something called heart of the wild that enables them to do massive damage in a feral form.