You want one or the other right? You either want something good to make your Friend Safari worth something or something downright horrible so you can laugh when you lie about having dittos knowing full well that all they will find is a ton of Luvdisc and Magikarp.
So what is the best friend safari you have found? What is the worst? What do you have?
I think mine is Water: Polliwhirl, Wartortle and Krabby.
Mine pretty much sucks. Sawk, Meditite and Hariyama - all of which are catchable in the game anyway and none particularly cool/in demand. I've got quite a few awesome friend safaris though, like Magmar, Charmeleon and Braixen. A few Ditto safaris and my both my favourites, Pawniard (Bisharp) and Toxicroak.