ME2 is definitely my favourite out of the three, but I still liked ME3 a lot, even with the ending. I didn't mind the wall-hugging stuff too much, even though it could kind of mess me up sometimes, but I just played on normal difficulty so generally it didn't hurt much.
ME3's combat is better, but ME3's combat is also just Gears of War but with worse controls. Yeah, I had a lot of fun. I've played a Vanguard since ME1 and when I imported my save from the last two games I was already super beefed up stats-wise. Nothing like biotic charging into a singularity with frozen enemies in the vicinity and destroying an entire platoon of enemies and then charging into another singularity because my cooldown immediately reset from a perk. That stuff is definitely cool, but nothing I didn't see in ME2. ME1's combat is slower and the wall-hugging is pretty bad, but the game in its entirety is just so much better than ME3. ME3's combat is done better in another game and the story is disappointing. It has its merits but it gave up too much of what Mass Effect was just to be a more able shooter.