[quote name='Ink.So.Well.']The reason you only got one achievement is because each squad member has to complete their own specific amount of side quest assignments and participate in main storyline missions.
Conveniently enough they leave the player to figure it out on their own. ;\
Ashley "Don't I Remind You Of Your Ex?" Williams - 15 Main Story Missions and 50 Assignments to complete.
Kaidan "Is This Awkward Yet? I Could Make It Awkward You Know. Just Give Me A Chance!" Alenko - 15 Main Story Missions and 42 Assignments to complete.
Urdnot "If Only MacGuyver Were A Bounty Hunter... In Space!" Wrex - 15 Main Story Missions and 41 Assignments to complete.
Garrus "Itching To Follow In A Certain Sith Lord's Footsteps" Vakarian - 15 Main Story Missions and 51 Assignments to complete.
Tali'Zorah "Fresher Than Photosynthesis" nar Rayya - 15 Main Story Missions and 46 Assignments to complete.
Liara "The Every Man's Other Woman" T'soni - 13 Missions and 51 Assignments to complete.
Thank you ME Wiki! I
love you.

[/QUOTE]
Lol, great descriptions.
The NPC that I liked the most were both Wrex and Tali. The others, I didn't really care much for them. But, I do like the fact that, at least according to the Mass Effect manual, Ashley was born in Brazil ; ) .
One thing they HAVE to do in the next Mass Effect is have some pigmy salarian called "Jan Jansen" who is a great inventor and strangely found of turnips. Man, if they made this character a DLC, I'd pay for it!