Mass Effect's combat is boring and predictable. Just look for chest high walls and you'll know when to expect a fight.
I wouldn't say Fallout's combat is anything special either, besides stealth combat.
Mass Effect combat's redeeming trait is Biotic and Tech abilities, they're really cool and require strategy if you want to be really effective.
Fallout 3 is a great game, I really enjoyed it, though I spent a lot more time playing Obilivion. However, after seeing Mass Effect's great voice acting and cinematics, it really became obvious how cheesy Fallout (and any other Gameboyo Game's) dialouge is.
