The ending was undeniably bad and people were right to shit on it (especially before the extended ending DLC which still didn't fix all that much), but I do find it annoying how it clouded everyone's judgement about ME3 as a whole and people act like the game has ZERO good writing or that it's the worst game in the franchise just because Bioware went full retard at the end. I'm in the camp that thinks that there was a ton of kino shit in the game before the ending that's well above anything that happens in the previous two games, plus, you have that multiplayer mode which I dumped a shitload of time into.
I still prefer ME2 a bit more just because I like the filler arc plot and how it's structured, but I've definitely spent the most time playing ME3.