Omaha with 5 hole cards.
Hands come together more easily than with 4 cards, so the bar for the nuts goes even higher. Pairs lose value and a dangler (a card with no connection or suit link to the other cards) costs more. Example: there are 10 two-card combinations from 5 cards (6 in PLO4). Double-suited hands are 46% and hands containing AA are 4%, both more than in PLO4.