Fortunately, Fink and MacPorts have brought back tools like Gimp, wget, nmap, and kismet to my arsenal... but still I miss:
- 3D cube. "Spaces" just ain't it.
- Flaming window effect... (oh man that was so cool)
- the vast application selection in aptget
- ability to use VIM/gvim/kvim ubiquitously
- simple script based init system was easier to manage
- ability to change file to program associations from a text editor
- virtual terminals
- hackable keyboard macros/keys (although the mac defaults are pretty damn good)
- custom keystroke to lock screen
What do you (or would you) miss most about your Linux desktop?