As one historic duel — the presidential race between Barack Obama and John McCain — ends, another heats up. The stakes are high: nothing less than the soul of rock 'n' roll. The competition is fierce. And you will decide — with your wallet.

In one corner is "Guitar Hero," the franchise that revolutionized the rhythm-game genre in 2005. In the other corner is upstart "Rock Band," which rewrote the rules last year by adding drums and vocals to the mix.

Each game has its strong and weak points, so if you're on a tighter budget, read on. (The prices here are for software only; guitars, drums and microphones cost extra.)

"Guitar Hero World Tour," Activision, for the Xbox 360, PlayStation 3; $59.99; Wii, PlayStation 2; $49.99"Guitar Hero" may be the sales leader in this category, but when its developer, Harmonix, went off to create "Rock Band," many fans defected too. "World Tour" plays catch-up by adding, yes, drums and vocals, but also includes a music studio that lets players create their own tunes.Most "GH" veterans will never crack open the music studio, and they won't be missing much: It manages the neat trick of being both simplistic and awkward. I did prefer the "World Tour" drum kit, which has one more pad than the kit for "Rock Band" and feels more sturdy and realistic."World Tour" stumbles, though, in recreating a full band experience. The menus to set up a band are confusing, and while you're playing it's nearly impossible to keep track of how your bandmates are doing. And unlike in "Rock Band," there's nothing you can do to bail out a struggling friend. The tour mode itself is really just a series of set lists, without the clever role-playing elements that make "Rock Band" so addictive.Still, "Guitar Hero" remains an enormously entertaining social game.

"Rock Band 2," MTV Games, for the Xbox 360, PlayStation 3; $59.99; Wii, PlayStation 2; $49.99When Harmonix unleashed "Rock Band" in 2007, it was already pretty awesome. "Rock Band 2" addresses most of the complaints about the original and adds some very welcome online features.That addictive tour mode I mentioned before is now available for solo players, so you don't have to wait for your friends to come over to enjoy it. You can also now form a band with friends online, and you can compete in "Battle of the Bands."The big advantage "Rock Band 2" has is its enormous collection of songs. It comes with 84 tracks, and you can transfer most of the songs from the original "RB" onto your "RB2" playlist. Add all the tracks that Harmonix has posted online over the last year, and you have about 400 tunes to choose from. That's enough to make even the surliest rock snob happy.