Joss Whedon is my master. You should join the two games I created (
gameID=27904,
gameID=27903) in silent tribute to him.
I've probably watched the show start to finish about four or five times. It never gets old. Far and beyond the best show I've ever seen.
In regards to Serenity, you have to consider the budget with which it got made. It was done on incredibly low budget, and barely got made at all. But I'll agree, the show is much better.
Unfortunately, FOX has the programming foresight of a lobotomized starfish, and canceled it. It joins the ranks of many other great shows (Arrested Development, Terminator: The Sarah Connor Chronicles, Family Guy, Dollhouse, need I go on?) that have spawned websites about how stupid FOX's programming decisions are. And on most of those websites, Firefly is cited as their prime example.
You aught to check out Dollhouse. Not as epic as Firefly, (Is that even possible?) but still good. It was also produced by Joss Whedon.