It's clearly Charlotte. US Airways has every gate in the B, C, D, and E concourses, save for jetBlue at D6
and Star Alliance partner Lufthansa using D12 for one flight a day.
There are only 14 gates (the 2 mentioned in Concourse D plus A1-12 used by everyone else) that aren't used by US Airways in the entire airport.
American Eagle: ORD
Continental Express: CLE
Delta Connection: ATL
Northwest Airlink: MEM
(ends Nov), ORD
United Express: IAD
The only routes that US Airways doesn't service from CLT
that a competitor does are SLC
on Delta, which is seasonal, and MUC
on Lufthansa, which is codeshare. Only 14 routes are served mainline at all on other carriers.
There are just 2 low-fare competitors, jetBlue and AirTran, serving only 5 destinations combined. Most importantly, Southwest does NOT have a presence, which is something Dallas can't say...Southwest's big operational base at Love Field makes them a competitor to the DFW hub.
[Edited 2008-08-09 16:33:30]