Just a quick 20mm comparison .
Liberation Miniatures, Elhiem Figures x2, and SHQ
Liberation Miniatures: Liberation has a large range of figures covering mostly the modern era infantry, some scifi figures, and they also carry the Hotspur range (IRC) of SCW Figures. These tend to be on the heavier side for 20mm miniatures, which I prefer for survivability reasons (broken ankles). Ordering is difficult since there is no shopping cart on web page, apprently ordering is done thru FAX. More good sculpts in pack than bad.
Elhiem Figures: Elhiem range also mostly covers the modern range from police to modern infantry. These tend to be medium sculpts and have great detail. My only worry is the thickness of the ankles, they are not kid or drunken gamer resistant like Liberation. Can be ordered directly on the web site or thru Syr Hobbs Wargames (great people) in the states. All sculpts in pack good.
SHQ: I have purchased a few figures (WWII and Vietnam) from SHQ a long time ago. They tend to be smaller than other figures and do not mix well. Hence I only have a couple of Vietnam figs left. More bad than good sculpts. Some poses just do not look right to me.
This is really subjective and depends on how you like your figures to look.