AA

A pocket pair of aces (pocket aces, simply aces, or AA) is the strongest starting hand in
 * limit hold 'em
 * no limit hold 'em

See those links for more information about AA in those specific games.

Nicknames

 * Pocket rockets
 * Bullets
 * American Airlines

Other games
See also:
 * AAxx in Omaha hi-lo
 * (AA)x and (Ax)A in seven-card stud