A number of characters really got shafted in ME3:
1) femShep -- think if you were hetero femShep who happened to need additional firepower and left Kaidan on Virmire, and romanced Jacob.
2) Jacob - I really hated his character assassination. (I'm a Liaramancer)... My second play of ME3 was with a Paragon who romanced Jacob. Ran into Jacob. Wow, we can get together again. Nope. She went full retard in the end and chose synthesis because she figured it was only the sudden stop that hurt.
3) If you weren't a Liaramancer there was too much Liara. If you were a Liaramancer she went dumb on you.
4) Insufficient dialogue with your crew... way too much autodialogue.
5) too many step and fetch quests and not enough real side missions.
6) Thessia? You've got to be kidding. That was it? Supposedly the shining jewel of the council races? And Liara with Goddess this and Goddess that and Okay Athame... yes... Athame, we get it, your mom was a Matriarch and a very powerful one, and she took you to the temple when you small (I know moms), and you're a prothean expert.......... But you never recalled any of the symbols or anything about the temple having anything prothean about it? Ever? -- Super Mac strikes again! -- This should have been our first stop.
7) The Cerberus Plot -- The Empire. Darth TIM and his ninja.
8) Thane.
9) The Crucible Plot while in itself not that bad because the way they screwed up stuff they needed an ass pull, but the way they mishandled it was just a head desk.
10) And the final insult -- Glowboy and Door #1, Door #2, and Door #3. And we don't even get to feel like we won the game. We get to feel like we lost. We get to feel empty. Don't forget this is March. We can't forget March 2012.
and addendum -- Ashley gets $100,000 worth of plastic surgery as a signing bonus and a fat promotion for acting like a ______ to femShep in ME2. I hated what they did to her character.