What other OSes offer by default, you will probably have to buy on Mac (nevertheless, it's better that nothing at all). Finder is really bad application - probably only better than iTunes and App Store. But TotalFinder makes transition to Mac a lot easier. It only offers some improvements, but every single one is spot-on, can't-live-without feature. Namely: tabs, show/hide hidden files, cut/paste files, folders first + dual mode which is really nice. There is also a Visor feature, but it's not for me.
You can try it for free for 14 days, but I bought it in the first 10 minutes. Must have.
They also have multiple desktop manager which I'm testing right now. It looks promising, but still not as productive as linux's desktop/spaces manager (but that's due to difference between taskbar and dock).
hah they now have your money