Logitech Wingman = best mouse evar! Oh how I miss that thing.
No but seriously, in times recent enough for me to remember I've had a Copperhead and a Diamondback 3G (I trashed my Copperhead so got the 3G as a cheapo replacement) the Diamondback was poor in comparison, the software with it is a bag of shit compared to what you get with the Copperhead and the tracking is noticeably worse, it's a decent mouse and perfectly usable but it really isn't as good as the Copperhead.
My bros G7 (wireless G5 basically) was lovely too, very good tracking, I'd say possibly better than my Copperhead but not by a lot but, like most Logi mice, they seem to fit bigger hands better and I'm a skinny bastard so it wasn't all that comfortable
Can't suggest much from the current range, couple of friends have a Razer Mamba and Imperator, not use either, Mamba got a big thumbs up but aparently the software for the Imperator is shite, lacks loads of the options that the Copperhead software used to have.
tl;dr: My choice for a cheap mouse = Copperhead