Yeah Mass effect as a series did pretty well on the npcs. The one that annyoed me the most was Vega. I did like him as a character or as a fighter. Avoided using him as much as I could.
If I had to pick a second place (Not counting DLC characters because most of them are bland exception being Jarvik) Would be kaiden because I can't remember anything interesting ever coming out of him. Then agian I did kill him off so never had his full experience.
I didn't find Jack or Miranda that bad but I really couldnt stand the asri justicare. She was just so boring.
As for a Favorite no question its Garuiss. one of the only who crew mates in all 3 games as crew and I really connected with his character and it was great to see him progress as the series went on.
Second probably Tali. Her species situation just really made me think and there was so much culture in her story line.
3 Javik I actually would have had him higher if I didn't feel like he was such a dick. He was one of the least likeable characters in the series. But the reason he is so high is because of how interesting he is and all the questions he answered.