For domestic flights I strongly perfer Midwest Airlines. Many flights are business class seats throughout the cabin and they serve chocolate chip cookies after 10am! What can beat fresh cookies?!
Continental is generally good too. They are usually quick to compensate me for any mistakes or delayed travel.
Another vote for Midwest! I feel like where many airlines feel like they're doing you a favor in simply getting you from point A to point B, Midwest tries to make the flight pleasant with the cookies (you even get two, not just one!) and comfortable seats.
Traditonally we have flown Alaska or Southwest for domestic flights, and for international we have usually flown British Airways. The last trip we took we went with SAS, and I didn't like it as much. The flightcrew is more hit and miss. On the way over they were rather blank acting, but on the way back it was wonderful. Almost made me miss BA, but not quite. The next time we go to Europe we are planning on using Air France- I'm so excited to have a direct flight to Paris from Seattle!!
Philippine Airlines Business Class and First Class
Cathay Pacific rocks! I just wish they have a nonstop flight to the Philippines.
and of course American Airlines... I always fly AA for domestic flights.