Oh man, the memories here...

1. Those early Thank You Points days! For some reason I recall the magic number being a $2700 domestic F itin - something like JFK-LAX R/T.

2. The US Airways Grand Slams. That was one where I owe my FT friends for showing me how it was done. Every Grand Slam turned into most of what I needed for 2 J tickets to North Asia and back.

3. The Hyatt FFN's and, in some years, a similar Starwood promo.

4. Marriott's promos were usually lame by comparison, except for one summer when you earned 5,000 DL miles per stay. I hotel-hopped some bad North Dallas Courtyards collecting those miles...room rates in the $30's. Although after the night when a drug bust went down outside my window, I upgraded to the finer area Courtyards which were closer to $45/nt.

5. Marriott Bonus Bucks, Extra Euros, and Premium Pounds. Back when paper certificates were a thing, the world was awash in those.

6. Probably my first Flyertalk-induced promo chase: Hilton's conquest bonuses. Every 4 stays yielded 54,000 bonus points in an era when a 6-night award at the HWV or HHV was 100,000 points. I hotel-hopped Doubletrees and Hamptons in and around Tampa during the course about a month of work trips and paid for 2 weeks in Hawaii. You weren't supposed to be able to repeat an individual conquest, but there were a few slightly-different conquest codes so people earned hundreds of thousands of points through them.