Being a tanker I don't have any major squad challenges, but I have a number of individuals.
DR7, Charger5, Dcat, Tyfoo, Mano, BTBrando, Litlblue, DFCrash, 27th, SMcgavin, Duce, traprr00, airjer, a8balls.
There are several others I can't recall at the moment. All these make AH fun for me, and hopefully I make it fun for them as well.
I also have a number of Bish friends that are awesome in gv's as well; Slaxer, Skeetr, fishngy, robopops, taxman, akmixer, shadowx, Hurless, damphyno, kilroy, IRNstorm, twcmav1, and one we lost MWK522. Again there are others I can't recall now, but I have the privilege to fight along side them.