I've always liked bid poker for the new strategy element it brings to the game. The game starts with an ante followed by the deal--five cards down to each player. Players review their hands and the dealer reveals one card in the center of the table. The player left of the dealer has the option of placing a bid on the card or passing. Action moves to left with each subsequent player either raising the bid or passing. Once all but one player has passed, that player pays his bid to the pot and takes the won card. He then discards to keep his card count at five. The same process continues until every player has had the first shot at an auctioned card. Finally we have the traditional poker hand of bet/raise/fold/showdown.
The pots can get large if players pay top dollar in the bidding process. The advantage is if you start off with trash, you can pass on the bidding, fold, and only lose your ante. I don't generally recommend bluffing in this game since hands have the potential of being very strong come the showdown. It is important to pay attention to what your opponents are bidding on and know whether to get out of their way and stop them from making their hand.
There may be a time when you should outbid an opponent for a card you don't need just to stop them from having a monster. For example, you have a strong full house--three aces and two tens, and your opponent has already bought a king and is bidding on another king. At this point you know the last king probably made him trips or a full house, which your hand trumps, but this new king would give him four-of-a-kind. This is when the game can get nasty since both you and your opponent are willing to spend a small fortune bidding on the card. There is a lot to think about, but in a different way then most poker variations, and that's why I like bid poker.