I'm not a fanboi. My main box is a 3700+ with 2G and a 7800GTX; my secondary box is a P4 3.4 with 1G and an X800XT.
If you're looking to build an inexpensive computer today, spend the extra $20.00 and buy the Pentium D 805 ($120.00 from NewEgg).
Yes, it's a P4. But its a dual core with the full cache. Yes, it's only 2.66Mhz on a 533 bus, but if you think about it,
thats its advantage and thats what makes it such a great deal - Intel isn't selling you a crippled product, they're selling you a full-sized Pentium D dual core that they've underclocked so that they don't cut into their mid-range processor sales. An idiot could figure out how to clock it up, just changing the FSB gives good results, and I haven't met anyone who can't get it to 2.8Ghz+ on air (I know someone who is running at almost 3.4 without liquid cooling).
Mad Shrimps has a great article on overclocking this processor.
It has EM64T support. Not nearly as nice as the Athlon 64-bit support, but it's still nice because you don't have to sit on the sidelines when 64-bit Windows Vista applications start to show up.
Does it have the punch of the AMD processors? No. But its a solid processor, and when Vista comes out and the game / application developers start optimizing for threads you'll be happy that you have that extra core.
If you had unlimited funds, I'd tell you to buy a nice, fat X2. But if you're looking for a cheap rig with good potential, this month the D 805 is your price premium.