My favorite method is the convincing control. The reason being (for those unfamiliar with the move) is that it leaves a card outjogged in the middle, so the spectators are convinced that their card is in the middle of the pack but it's really on the bottom. Great move. Since you never mix up the cards and you leave "their card" outjogged, it really hammers it home to the spectator that there's no way you can control the card. You can set the deck down with the card outjogged and cleanly push it into the middle, and unbeknownst to them, it's already on the bottom.
Jay Sankey teaches an easy version on some of his dvds (Extremely Ambitious being one of them). My favorite version though is Ernest Earick's one handed convincing control as it positions the card for a perfect bottom palm. That's in his book By Forces Unseen. I also know on dan and dave's site there is the new AP Spread Control but I have only seen the demo so I can't say if it's good or not (but it does look quite good that's for sure).
Hope that helps! And I'm also sure you can find it on youtube or something.