I strongly disliked the gameplay of ME1 until I played Engineer and really discovered how fun powers and the like are.
I still like ME2 gameplay more, I find it more tense and faster. I have to say I disliked ME1 more with each playthrough thanks to the atrocious Mako and sidequesting but I still enjoyed it plenty. To say the story is the only good thing about it is going a bit overboard imo.