I'm always in for solo games (DMing is off, as I don't have that much time at the moment). I've been in a few before, and the characters that work best really are those who can survive all by themselves and are jack-of-all-trades in a way or another. Then must be able to fight and/or have knowledge of spellcasting, must be able to survive by themselves, deal with traps, hide, sense, and talk nice to people. Solo is the kind of game where support classes (bard, ranger, warlock, monk-ish, dragon shaman, marshall...) really can shine (because there's nobody to outshine them, OK, granted). Anyway, I'd suggest either high-powered chars (a bit more than a 28 point-buy...) or gestalt.