Only finished the first game on PC and then changed to xbox 360 because my PC couldn´t handle them lol xD Anyways, probably my favourite game series ever....never gotten so powerfull emotions from any media as when i finished Mass Effect 3, after playing through the whole trilogy and importing my character from the start. I´m not ashamed to say that i had some manly tears ;D I think the ending(s) were fine....could have been better, but it didn´t ruin the series for me at all. Perfect triloy of perfect games in my opinion!
The first 3 games are perfect. The ending caused a lot of controversy but you've got to remember that no matter how you personalise it, it's Shepherd's story.
Also, the only gameplay difference between the console and PC versions is that in ME1, you can online command your teammates as a Pair on the console version.