Best AH compendiums/compilations

[Melvin Loh]

Guys, which compendiums/compilations of AH works do you reckon are the best ? Would y'all consider all of the WHAT IF? series by Robert Cowley as among them ?

 

[luakel]

Have any of you guys read the series of Greenhill "_______ Victorious" books edited by Peter G. Tsouras? I think they're pretty good.

 

[Straha]

GURPS Alternate Earths, GURPS Alternate Earths II and Gurps Infinate worlds