Funny, I don't really find any of the Empire companions "hot"... well, maybe a customised Raina for the looks, but I did find her a bit bland/generic to be honest.
1.) Vette... more of a "little sister" thing. She is someone to have fun with, but I feel the need to protect her more than than anything else.
2.) Mako... again, she is more of a person I would feel the need to constantly look after. She is just too adorable, but all in all feels a bit too weak to be considered hot for me.
3.) Kaliyo. If you've had a psycho/sociopathic gf once, you probablydon't want another. And Kaliyo does not even have redeeming qualities in the looks department.
4.) Jaesa I feel there is more of a mentor relationship going on. What can I say, I like my Jaesa Light Side.
5.) Raina... Well, the looks are there, but I don't get any vibes from her personality.
Republic on the other hand surely does do hot. Makes me question my choice of faction a bit here
Forgot the worst of the lot! Ashara. While yes, she could be considered cute, her personality just flat out kills it. She is weak, pathetic and constantly blames you and everyone else for her lack of a backbone. Of course you had a choice, you idiot! But I guess it's far easier to just join the Sith than to step up and take responsibility for your actions. Duh.