none. just shaved my head down to the stubble a few days ago.
back when I did have long hair, though, the products I used depended on the look I was going for. for just every day stuff, I either pulled my hair back into a ponytail or let it go free. for parties and such, I either hairsprayed it into some extreme style (ala Flock of Seagulls or Robert Smith), or used pantene curling gell to give it a wavey-ish look.