Whatever game suits you best, learn to play both Limit and No Limit Texas Hold'em. Your overall game will definitely improve.
If you want to make money playing poker, find a game with a few suckers, fish, donkeys, live ones, or whatever you choose to call a bad player. Just don't let that sucker be you.
Tournament play demands patience to survive and win. Winning at cash games demands a whole other level of thought and deception. You need to reach into your bag of tricks and run the occasional big bluff to be a consistent cash game winner.
I am most challenged by playing cash games against the world's top players. These games force me to think several moves in advance, like in a game of chess. And though I also find tournaments fun to play, they just don't provide the constant brain buzz that cash game players crave.
In poker, you want to play the weaker guys. In chess, it's the opposite.
If you see me playing a $1/$2 no-limit on PokerStars, I'm probably experimenting with something, trying something new seeing how it works.
I remember seeing the song in some diners on the selection gadget that plays records at the table while you were eating. We were never told if the songs ever got on any charts.
In poker, you've got to start at the bottom level and work your way up. This advice applies to the limits that you play and the sizing of the bets that you make.
Never underestimate the importance of preparation for any single poker session or tournament.
