I passed Mass Effect 1 two weeks ago, ordered Mass Effect 2 and am somewhere in the beginning. I was never into sci-fi games but I've heard many recommendations. Same story as with Dragon Age - I was never into that kind of games but decided to give it a try and was very satisfied.
Imo Mass Effect still isn't as good as Dragon Age. Actually nowhere as good. But it's a good game nevertheless. Dialogues are boring and very simple - my character often says different things than I want him to say because choices are confusing. Also after my second playthrough I found out that different dialogue choices turn out to make my character say the exact same thing, no matter which one I pick. Which really sucks. Quests are very repetitive, there's no real reason to earn credits, gaining xp and leveling also isn't too great since gaining 2% to accuracy or damage really isn't rewarding.
Yeah, I'd rate Mass Effect 1 - 8,5/10 and Mass Effect 2 - 7,5/10 since ME2 has improved graphics and gameplay but adds elements that really suck and boosts ME1'a annoyances to another level (for example even less leveling and introducing ammo limits, removing Mako, planet surveying and exploration that suck etc.).
Of course I still think that it's a good game though. I think I just expected more after passing Dragon Age. Mostly because people were saying "if you liked Dragon Age you will love this game". Also I think that these dialogues are mad overrated. I think they are way too simplified in this game. At least after playing DA these dialogues in ME really seem to suck but then again Dragon Age was amazing in this matter.