I might have to correct myself. This is from USA Today in April. Can't imagine things change much so it's probably still somewhat good.

Incidently, I'm freakin' marooned at IAH right now waiting for my flight to PDX with 2:20 delay putting me into PDX at 1:25 am (earliest).

WHEEEEEE!

. ATA Flight 4234 from Houston Hobby to N.Y. LaGuardia (late 100% of the time in April).
1. ATA Flight 4233 from LaGuardia to Hobby (100%)
3. ATA Flight 4232 from Hobby to LaGuardia (96.55%)
4. Continental affiliate ExpressJet Flight 2669 from Newark to Kansas City (96%)
5. United affiliate SkyWest Flight 6174 from Monterey, Calif., to San Francisco (89.66%)
6. ATA Flight 4220 from Chicago Midway to LaGuardia (88.46%)
7. United affiliate SkyWest Flight 6212 from San Francisco to Sacramento (86.67%)
8. American affiliate American Eagle Flight 4659 from Newark to Raleigh/Durham (86.21%)
8. Continental affiliate ExpressJet Flight 1205 from Charleston, S.C., to Newark (86.21%)
8. Southwest Flight Flight 488 from Salt Lake City to Denver (86.21%)
11. Continental affiliate ExpressJet Flight 2665 from Detroit to Newark (84.62%)
12. US Airways Flight 465 from Newark to Charlotte (84%)
12. Continental affiliate ExpressJet Flight 2567 from Nashville to Newark (84%)
12. Delta affiliate Atlantic Southeast Flight 4672 from N.Y. LaGuardia to Baton Rouge (84%)
15. US Airways Flight 949 from Philadelphia to Los Angeles (83.33%)
15. United affiliate SkyWest Flight 6212 from Sacramento San Francisco (83.33%)
17. Continental affiliate ExpressJet Flight 2567 from Newark to St. Louis (82.76%)
18. Continental Flight 1155 from Newark to Atlanta (80.77%)
18. ATA Flight 4209 from LaGuardia to Chicago Midway (80.77%)
20. 14 flights tied for 20th at 80%