I would say my favorite game is definitely good old Texas Holdem. It is undoubtedly among the simplest to grasp and most enjoyable to play.
PLO is the game for you if Holdem seems a little slow or monotonous and you want more excitement. I would not advise playing it until you have a solid understanding of Holdem and Poker in general because it can be daunting at first, especially for poker newbies. Of course, Holdem and PLO are the two most popular games right now, but that does not mean the older, less well liked variants are any less entertaining. Razz, some of the split Hi/Lo games, seven-card stud, five-card draw, and other variations are entertaining as well. However, they are a little more intricate and challenging than traditional holdem.