Please Help!

So I'm gonna be building a desktop soon, and I want it to connect wirelessly to my router. Is there a preference as far as buying an internal wireless card as opposed to a USB wireless adapter? I'm gonna guess and say the wireless card is the way to go, but why?
 
Just wondering if there's a winner as far as getting the best wireless signal to my desktop, thanks.
 
EDIT - I noticed on newegg, there's wireless cards stating they're "IEEE 802.11b/g." Does that mean they don't take advantage of wireless N networks? Or am I completely off base here?

 I assume a solid wireless card would be preferable, but I use the ethernet cord like a REAL MAN so I don't know. I have used a usb connector before, however, and it seemed pretty solid. Kind of depends on the router, I guess. 

PCI: Whip antenna for better signal, not having something hanging off your PC and taking up a USB port, maybe a little performance boost since PCI uses a separate bus with DMA but probably nothing you'd notice. 
 
USB: Jab it in the socket and go.

@DrunkenKong:
Using a wireless adapter for your PC seems like a waste of the gigabit router you just bought, IMO.  I'd hardwire it.

Going wired should always be first choice but if you are to go wireless a PCI card is the way to go, hell I have one in there just in case.

I've always used wireless, including for my desktop.  I just hate cables/wires in all forms.  iMac has a standard internal card, works great and I can recommend it.  Speed is fine too, I've never felt it necessary to have a wired connection instead.
 
USB adaptor seems to be more ideal for retrofitting wireless when you don't already have it, but the card seems the way to go for doing it while constructing.