Ive used multiple distro's of Linux on VMWare. I think its a great program, although it does hog resources alot, there isnt really an effective/elegant way to get around this.
I have had no problems with Mandrake 8.1 and above, red hat 7.1 and up and slackware 8.1.
I really want to get into gentoo linux (more so for a personal preject) but I think that it would not configure as easily using the virtual machine as the other distros do.
One thing to make sure to do is install vmware tools. Sometimes it doesnt work when clicking the link or using the menu function so I think it was Admiral_LSD who posted the link for me awhile ago and
here it is.
I usually set it up to use 192 megs of RAM and 3 GB file for the installation.