Why play poker? It seems like a simple question, but the answer is both complex and personal. There are many different reasons to play or not to play poker. Often, the reasons a person has for playing poker will shed light on what type of player that person is and what limits and games he should play. Social rewards. This is a major reason behind the traditional home game. Many friends like to hang out and play cards, and many people become friends over the card table. If this is one of the major reasons you wish to play, stick with low stakes, where the games are more fun and friendly.
Entertainment. Poker is a competitive game. To win, one needs the skills and the bit of luck the game necessitates. Many find this enjoyable and compare poker to playing a sport. Make sure you don't get swept up in the 'entertainment' nature of poker, because it is possible to lose a lot of money at the game.
Education. The skills necessary to become a good poker player apply well to other aspects of life. Poker will help you to improve your judgment skills (reading people) and sharpen your logical and strategic skills (how to play your hand).
To make money. Most people play poker for fun, but some make considerable money at it. Of course, these people are few and far between. Not everyone can make a lot of money from poker. Nevertheless, the desire to win more is definitely a reason to improve your poker skills.
Poker is one of the few forms of wagering where you can actually win. Casino-style betting is rigged against you (it is impossible to win in the long run at craps, roulette, etc., no matter what anyone says. The only exception is blackjack if you count cards, which is extremely difficult). Sports betting is also nearly impossible to beat without insider information. Thus, poker is one of the few forms of gambling where one can actually win money in the long run simply by being good at the game.