One fairly scary build is the generic warrior from UA, with Favored Enemy for all 6 of the bonus feats. Each time you take it, you get a +2 to an already-selected enemy. This means your 10th level character can have +12 to damage and Bluff, Listen, Sense Motive, Spot, and Survival versus Humanoid (Human), in addition to the full BAB progression and d10 hit dice. If elves and half-elves are very popular in your party, you can use Humanoid (Elf) instead. If your party is six different characters of six different races ... well, try something else.
Alternately, since you're getting a big bonus to Bluff, take +4d6 sneak attack as two of your bonus feats, and settle for +8 to damage and the skills. If you do this, you simply must spend two of your normal feats on Combat Expertise -> Improved Feint.