The only reason to pay for a Windows box is for game playing and game development ( the later isn't really even true)...if you're really interested in programming and you don't have a corporate budget, i don't see how you could go with anything other that linux or the free unix derivitives. everything you need for any language is free...free CORBA broker too...can't beat it...free
i personally run both. without tfc, i don't think windows would be a priority....