XP Home vs. XP Media Center vs. XP Pro

[QuickLearner]

I'm about to buy a new desktop. For online poker and Pokertracker is there one preferred OS or will all of them work fine?

I won't be networking the PC (in the workplace environment sense), so I expect that XP Pro isn't needed. The Media Center is attractive, but I don't know if the added functionality will make the OS more fragile.. Should I stick to XP Home? Thanks for helping.