I'm not a very experienced UNIX developer by any stretch of imagination but I enormously appreciate its command line utilities and just how much they make my life easier. I grew up using DOS command line (and before that ZX Spectrum's line editor!) and to this day the task I most commonly run (Win+R) is "cmd". On top of that, the very first thing I install on a new box is "Open Command Window Here" Explorer context menu option! So even though I got exposed to UNIX relatively late in my career (so far) I quickly learned to love its tools (except vi!) Since I've been exposed to them I had to start using UNIX command line tools on Windows as well. The port I use is called UnxUtils and can be found here. It's not a full port but it works for me. Actually seems to be a set of ports of GNU utilities and as we all know "GNU's Not Unix" but whatever - it works great for me.
Btw, I'm looking forward very much to Windows PowerShell (The Shell Formerly Known As Monad) A very very cool piece of technology (with now a very lame name but that's a lack of geekiness in MS marketing divisions for you) Microsoft is finally getting its game up for command line. I just wish this was released already!