Many posts will tell you what hands to play pre flop.

These are hands that shouldn't be played preflop at a full table.

Big little hands, suited or not.
Cards that dont connect as a straight ie: k6, q7, j3. hands like this have no future unless you hit 3 of a kind (not likely).

A9 through a6, although suited helps these hands with less players.
If you hit your ace your kicker sucks. the reason a5 and less (suited is best) are playable is you have more outs to a straight.

im also not a fan of small pps 22 to 66 unless you can get in cheap.

any thing i missed?