From what I know up to this point, I think these are my favorite Amagami girls:

1. Kaoru ------- the most down to earth character I think. She's a caring person too.
2. Tsukasa ----- Smart and responsible. I like her with a caveat.
3. Ai ------------ Straightforward and...
                          

4. Haruka ------ Fun, but also eccentric and a little too casual for me. Too high maintenance.
5. Sae ---------- Cute, but probably has the least developed personality
6. Rihoko------- Easy to talk to, but a bit clumsy. Don't know what her best features are.