i'm all for boss fights, long as there done right as in games like Shadow of the Colossus, Devil May Cry ( pretty much all cept 2, but it sucked all over anyway >.> ) Metroid Prime and God of War ( an i'm not even a fan of the seires) all pretty much play as 'this is how you do boss fights'
RPG's >.> boss fights tend to boil down to a lot of the same issue FPS bosses have, IE spam ( attack/weapon) till it dies, side bosses usualy put up a better fight and require some planning, but not the main story ones most the time.
DarkSiders has MASSIVE difacultly issues with The Black Thrones boss, Straga being the easyest and most BOREING boss ever, with The Griever coming in a close second, while the other bosses, still piss easy where still kinda fun. Uriel (2nd time) was the closest to a real boss the whole game.