I don't mind grinding if the combat is enjoyable. I generally find combat in WoW to be boring, same in Rift and almost every other MMO I've played. In the few where it didn't feel boring, it felt too much like gambling.
Grinding in Diablo 3 is fun. I can waste hours clearing content I've already cleared, simply because the combat itself is enjoyable. Grinding in WoW consists of me pressing two buttons (yes, on my Druid) until sh*t dies. Not a lot of excitement involved. Grinding in GW2 is sort of fun, but you can't really grind. You pull more than two of almost any kind of enemy, you're dead. Rift would be entertaining if the animations weren't so damn bland. EVE Online grinding is 10% action and 90% clicking radial menus to do sh*t.
Edit: They should make a Diablo MMORPG. I would grind dailies all day if it involved the over-the-top physics and spell effects from Diablo 3. Just not an isometric one... gimme 3rd person view, plx.
Edited, Apr 15th 2014 10:53pm by Mazra