Yeah, it really is fantastic. At the very least just make sure you give the first episode the patience it deserves - it's a great episode but admittedly it takes a while to warm up. It's a little off-putting on first viewing, but causes no dramas on later ones.
In my personal opinion, Firefly's half season is right alongside the first three seasons of Buffy.
I love all of Joss' works, but I 'merely' enjoyed Angel and the later Buffy seasons, rather than being as jaw-droppingly amazed as I am with Firefly and early Buffy. Later Buffy is still great compared to other shows though, but just not in comparison its own earlier years. I'm talking about the seasons on the whole, though - there are still some amazing individuals gems throughout.
Haha... sorry for seemingly going off on a tangent, but I just wanted to convey in what esteem I hold Firefly.