The most popular handheld gaming systems, of course, are Nintendo's DS and DSi.
The best handheld system, in my mind - especially for hardcore gamers - is the Sony PSP 3000. I like the PSP 3000 over the DS options because of better graphics and a more realistic gaming experience. There are more adult-friendly titles available, plus a built-in microphone, Wi-Fi and integrated Skype service. The new anti-glare screen allows you to play outdoors and still be able to see the action.
But while the DS and PSP are great handheld systems, there are two serious contenders to the throne: Apple's iPod Touch and iPhone.
Yes, you've got to download games, but the games are relatively cheap. Madden football, for example, is $6.99 instead of $19.99 or $39.99, like you sometimes find for traditional handhelds.
You can download multiple free titles for the iPod Touch that aren't bad, including trial versions of games. And while Sony's new download game system is good, it cannot yet match the selection at the App Store.
A lot of people already have iPods and iPhones and don't have to pay for new hardware, and being able to have one device do the job of several gives youngsters (and the young at heart) one less thing to worry about losing.
I hadn't really thought about the iPod and iPhone as serious contenders to the big two in handheld games until my mother bought my son an iPod Touch for Christmas.
My son has the Sony and Nintendo systems, but enjoyed taking his $25 gift card to the iTunes store and purchasing games as well as downloading free ones. I thought the newness might wear off and he'd go back to Mario on DSi, but he's always on his Touch, checking the weather, getting sports updates, listening to music, searching the App Store for free games - or begging Dad for another gift card.
The full-color screen on the iPod Touch and iPhone presents games at least as well as the other two, though the touchscreen controls take a while to get used to. But when money is tight, buying one device that can do a lot of things well might be better than buying another that is only truly good at one thing.