I get whatever is decent bang/buck and allows me to clock the nuts off it.
Which is why I just bought a 4890
1ghz daily clock here I come
Had a 260 192, 280, and 260 216 55nm and I've got to say they just aren't as fun to clock as ATI cards. Also having to purchase separate waterblocks for them is a huge factor as well :/ I'm still using the same waterblock that I had on my 7900GT!