5 Card Draw 

3-7.

5 cards are dealt down to each player.

There is a betting round after the deal. After the betting round, each player may exchange up to three cards. Another round of betting ensues, followed by the showdown. With fewer than six players, a player may draw four cards if they show that their remaining card is an Ace.

High hand

Adding wild cards to play (and allowing five-of-a-kinds if chosen).
High/low: the highest hand and lowest hand split the pot.
Lowball: Lowest hand wins.
Allowing for four card draw with an ace.
Double Draw: After the first exchange and subsequent betting, there is another exchange and betting round.

All For One or One For All 

3-10.

5 cards are dealt down to each player.

There is a round of betting. Each player, starting to the dealer's left and continuing clockwise, may choose to either draw one more card or trade in all his cards for an equal number of replacements. Rounds of betting and drawing/exchanging continue, the leader rotating each time, until there are fewer cards in the deck than players left in the game.

High hand.

Anaconda 

4-7.

7 cards are dealt down to each player.

Each player passes three cards to the player on their left after the first round of betting. After the next betting round, each player passes two cards to the player on their left. After another betting round, each player passes one card to the player on their left. Each player then chooses five cards to keep and discards the remaining two. Each player who chooses to remain in the hand places their 5-card hand face down in front of them. Play continues with a roll and a betting round until each player has rolled four cards, after which time a showdown ensues. The cards speak for themselves.

The high and low hands split the pot.

1: The cards are passed to the player on the right.
2: Each player keeps all seven cards after the passing and chooses among all seven cards to turn up. This allows the player to more easily change from high to low depending on what is being played (or to declare both).

DogButt 

3-7

Same as 5-card draw.

Same as 5-card draw, except, as in Baseball: 3's & 9's are wild. A 4 gets a player an extra card.

High hand.

Don Juan 

3-8.

Three cards are dealt down to each player.

There is a betting round. Each player in turn beginning at the left of the dealer may discard from 0-3 of their cards and draw replacements from the deck. There is a betting round. There is the showdown.

Low hand (A-2-3 is lowest).

Players pay a set amount, such as a dime, for each card replaced in leiu of the first betting round. After the draw, players proceed to play their three cards as in 3-card guts, either staying in or dropping depending on the degree of confidence each has in his hand. The remaining players have a showdown for the pot or the privilege of mathcing the pot or pot match limit. Play continues until only one player stays, as in guts.

Howdy Doody 

4-7.

7 cards are dealt down to each player.

Same as Anaconda, with these exceptions: Threes are wild if and only if the hand they are in is used to try to win the high hand. Kings are wild if and only if the hand they are in is used to try for the low hand. There are no betting rounds until the showdown.

High and low hands split the pot.

The low pot is usually won by a perfect low. High is usually won by at least a full house.

Jacks to Open, Trips to Win 

3-7.

5 cards are dealt down to each player.

Played like 5-card draw, with the following differences: Only a player with a hand as good as or better than a pair of Jacks may open the betting. If someone has such a hand, they may open the betting. If nobody can open, the hand is discarded, everyone antes again, and hands are redealt. Once the betting is opened, play continues as in 5 Card Draw until the showdown. At this time, anyone who has 3 of a kind or better is eligible to win the pot. The best eligible hand takes the pot. If nobody has an eligible hand (that is, nobody has at least 3 of a kind), then the hand is discarded, everyone antes again, and hands are redealt only to those players who have not folded this hand or a previous hand. If, on any given hand (regardless of eligibility), all but one player folds his hand, then the surviving player wins the pot, thus ending the game.

High hands wins the pot.

Progressive: If nobody can open, the requirement increases to a pair of Queens, then Kings, then Aces, then goes back to Jacks, etc.
No Trips: Just play with Jacks-to-Open, but only openers to win.
High-Low Split: The high hand and the Low hand split the pot.
Limit Number of Hands: Set a number of hands (like five) to play regularly. If nobody wins after that many hands, then play 5-card draw normally, anything (guts) to open and anything (guts) to win.

Monkey Love 

3-6

As in 5-card draw.

Players declare how many cards they want to draw simultaneously. The player to your left gets the cards you discarded.

Neuticles 

4-7

7 cards to each player.

This is essentually Anaconda with no passing of cards. Each player chooses their best 5-card High or Low hand from the cards they were dealt. Four cards are rolled with a betting round before the first roll and after each roll. There is a showdown after the last (fourth) roll and subsequent round of betting.

High and low hands split the pot.

Large Neuticles: 7 cards dealt to each player.
Medium Neuticles: 6 cards dealt to each player.
Small Neuticles: 5 cards dealt to each player.

Pick a Partner 

4, 6, 8, or 10.

5 cards are dealt down to each player.

Everyone rolls a card. Highest card showing picks one of the other hands as a partner. The next highest unpartnered hand chooses a partner, and so forth until everyone is paired up. Each partnership combines their remaining 8 cards and chooses 3 of them. Three rounds of betting follow, with one of the 3 cards rolled after each round. The winning team splits the pot. If one member of a team folds, the other can continue playing and, if he wins, he wins the entire pot.

High hand.

Threes 

3-5.

Five cards are dealt down to each player.

Similar to 5-card draw, except there are three drawing rounds with betting rounds betting rounds before, between and after. The player is allowed to draw up to three cards per round (no four cards with an ace). Threes are wild.

High hand.

Don't throw away threes.

Trees 

3-10.

5 cards are dealt down to each player.

There is a round of betting. Each player can now trade cards freely with every other player. Any number of cards can be exchanged, but a player must give the same number of cards he is receiving. When all no more trades are forthcoming, there is a final round of betting, then a showdown.

High hand wins the pot.

Triple Draw 2-7 

2-6

Deal 5 cards to each player, as in 5 card draw.

Each player is dealt 5 cards and the goal is to make the lowest possible 5 card hand. There are four rounds of betting and three draws in this game. After each round of betting, players choose cards to discard ... anywhere from 0 to 5 ... and the dealer deals them replacement cards. After the third and final draw, there is one last round of betting. A dealer button determines the order of betting and discarding.

Players try to make the lowest possible 5 card hand. Aces play for high only and deuces play for low. Because you are trying to make the lowest possible hand, straights and flushes count against you. This means that 23456, for example, is a very bad hand. It is not considered a 6-low. It is a straight and is therefore worse than holding AKQJ9. The best hand is 23457 unsuited.