Krogans, partly because they are reptillian, partly because Wrex is ultimate awesome and partly because I can't help but feel sorry for them given that their once proud warrior culture has faded in the face of slow extinction.
Also Turians again because I'm pretty sure they are reptilian and because they have honor codes.
Also Asari.... this is mostly hormonal I'll admit but there is some good things they do as well, what with their biotics and stuff.
Oh what the hell, I really love all the races. I ain't no racist.