Most of the Texas Holdem or Holdem games you mentioned pokergirl40, can also be played together in multi-game tournaments.
In these types of tournaments a player has to stay on his/her toes and watch for the game switch.
Most of the time though, I will play a Texas Holdem by itself as no limit in a tourney or in the game of HORSE.
Online Poker sites have come a long way with their poker games, where there's a wide variety to choose from and they change-up or add different poker games to make them more challenging for players.
I like these different games, because I like a challenge.