I run 1600x1200 with 3/4 sized icons
What matters more is your screensize to resolution ratio. 3/4 slots on a 22" monitor running 1600x1200 reso is acceptable. Too tiny on a smaller monitor at the same reso.
Type of monitor also maters. Most flatscreens and some really cheep CRTs aren't sharp enough for decent viewing at a really high reso.