While Samus generally drops a few spots on the tier for teams, if you play her right then she can still be pretty good.
In my experience, Sheik, Fox, Peach, and Marth all team well with Samus, however those 4 pretty much all team well with anybody.
HugS and Omar (bloodOfTheFallen) team with Samus and Sheik. ShadowCloud and I have done pretty good with Samus and Sheik as well, but not nearly as good as HugS and Omar. I can't think of anymore off the top of my head that have done well recently, but yeah. Sheik, Fox, Peach, and Marth should all do well.
Sorry Watty and Crashman, I have no idea who you guys team with =/ I'm sure you both do very well though regardless ^_^