Not mentioned but worthy:
Ardor: Those crazy Italians and the great smoking art pieces!
Cristiano: I got one on a whim on ebay... LOVE IT. Got another about 3 weeks ago. LOVE IT TOO.
Il Duca: OMG. Just OMG.
L'Anatra: Who doesn't want to have a bird on your stem?!
Pipa Croci: Great pipes, great prices.
Randy Wiley: Just a damn fine carver.
Tsuge: They did a GREAT job with smokingpipes.com getting a lot of entry level pipes out to the community at VERY reasonable prices and everyone here or anywhere else that got one raved about them.
+1 to (in no particular order)
Charatan (ok, there is a bit of an order. Love these)
Dunhill
Comoy
GBD
Big 3 (Petes, Savs, Stanwell)
JHW
Rad Davis
Kirsten
Castello
Cavicchi
Radice
Ser Jacopo
The Oldies (Tom Howard, KB+B, Linkmans, Marxman, Weber, Custom-bilt, and WDC)
EDIT: AND Neerup! Everyone loves them, no one talks about them and they make the new 4th Gen pipes which are lovely!