For me, Mass Effect 2 was absolutely epic, but certainly not perfect, it has flaws, there are things that ME1 does better than ME2, such as being able to gear up your teammates, I think that's most basic thing in games nowadays, and in ME2 you just can't do any customization on them, even Garrus has to keep using his damaged armor, and he doesn't even heal from his injuries on his face throughout the whole game (while you, recovering from clinical death and total body mutilation requiring implants everywhere can heal by simply be good-minded... that's a pathetic overlook by BioWare considering how they usually are looking at details like that).
Additionally, the DLC-specific armors (Collectors' armor and so on) all have a permanent helmet on, not to mention that the Blood Dragon armor's design and looks doesn't even fit the context at all in my opinion especially not with a freaking dragon painted on it, and the third armor (its name escapes me since I hate it anyway) is ugliness incarnate, and it looks pathetic when your Shepard's drinking animation goes through the helmet itself, another formidably stupid obvious thing that apparently wasn't obvious enough to fix.
And, finally, the scanning minerals process mini-game is of absolute boredom and gets extremely repetitive fast, especially considering that if you "chose" (not really) to not rely on resources found by that mini-game for everything that costs resources and only accumulate the resources that you do find during most missions (from containers and such) then you barely have enough to pay for not even the third of the researches you can get, so it's literally forced on the player. And to add insult to injury the only scanner upgrade that is available does absolutely nothing to "greatly speed up the scanning process", either I missed something or I had to "install" it... or I don't know, but the damn thing was just as imprecise and slow as the "original" scanner.
I do have other complaints about ME2, but overall it IS better than the first, and is certainly darker. Also Tali is awesome.