<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by moondog:
1) AA - great availability (I've never not been able to redeem at the cheap level), awesome international upgrades, good partners, and domestic awards allow stopover PLUS open jaw
2) UA - while the availability isn't too great, they fly lots of places I go. Also no fees for last minute bookings
4) NW - no advance booking fee, first class for elites on Y awards per normal upgrade procedures, 30K intra-Asia in business class which can be split with Y
5) DL - good availabilty (IME best other than AA), decent open jaw/stopover rules on domestic awards
7) WN - while I understand the utility of WN awards, they just don't fit my travel patterns, hence the low ranking
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I've had good pile of miles in AA, UA, NW, DL, and WN. I've been able to make great use out of UA nad WN, but the AA and NW have just sat there. For domestic travel, UA and WN allow last minute bookings. The others charge fees if not booked far enough in advance. While I have planned AA trips far in advance, the purchase cost was always quite low, and they seldom had my desired flights available for sale.
I've never had a problem with UA availability, even on thin routes, though the availability seems to come and go. However, stopovers would be nice.
Northwest does allow mixing and matching of award redemption for round trips which can result in some strange mileage requirements. But I haven't had a chance to use them yet.