From my open flights. Counts are slightly lower as I am a bit behind, but the top 5 are still accurate.

Top 5 Airports:
1. Greenville-Spartanburg (GSP) 150
2. Ronald Reagan Washin (DCA) 117
3. Charlotte Douglas In (CLT) 48
4. Washington Dulles In (IAD) 33
5. Hartsfield Jackson A (ATL) 31

Top 5 Airlines
1. US Airways 165
2. United Airlines 27
3. Delta Air Lines 18
4. AirTran Airways 11
4-way tie for 5th:
All Nippon Airways 2
Midwest Airlines 2
British Airways 2
World Airways 2

Top 5 Aircraft:
1. Canadair 200 147
2. Canadair 900 10
3. Boeing 717 8
4. Airbus 319 7
4. Boeing 737 7
4. McDonnell Douglas-88 7

Top 5 Routes
1. DCA↔GSP 110
2. CLT↔GSP 22
3. MDT↔CLT 19
4. ATL↔IAD 12
5. IAD↔GSP 11