Upgrade lover,
Welcome to FT!
The only major airlines that offer unlimited couponless/sticker upgrades are CO (w/hubs in IAH/CLE/EWR), NW (w/hubs in MSP/DTW/MEM) and US (w/hubs in PIT/PHL/CLT). The other airlines UA/AA/DL require middle tier elite members to pay for upgrades. The above is under the assumption a discounted coach ticket is purchased. Some airlines are more flexible with upgrades on full Y fares and more expensive coach fares.
I am also a very avid fan of TW and love their upgrade policy but now must pay to ride upfront on AA
A lot of airlines will comp you elite status. I know CO will without a doubt but I hear NW is really difficult to get a comp. UA comps easily as well.
The best solution is to see if you are willing to live with paid upgrades or upgrades for GRATIS! Also, what points of connection work best for your travel.
[This message has been edited by NW,CO,TW only (edited 06-25-2001).]