The P35 chipset is still incredible value for gamers. The P45 offers some improvements, but nothing you can't live without at this point. The G33 and G43 are not for gamers, they have integrated graphics. The X38 and X48 are designed for rich gamers and extreme overclocking.
No matter what you build today, your next PC will likely be using the next generation Intel socket and chipset, so don't worry about future compatibility at the moment. We're about to go through a pretty significant change, a socket change and new RAM type (DDR3) doesn't happen every year.
No matter what you build today, your next PC will likely be using the next generation Intel socket and chipset, so don't worry about future compatibility at the moment. We're about to go through a pretty significant change, a socket change and new RAM type (DDR3) doesn't happen every year.