I agree Fly-5 with SAS was really something... you had to mail in boarding passes so you could actually credit to UA and then send bp's to SAS (they didn't have a problem with this, the UA FF number was on the bp). I think I spent $600-700 for the 10 intercontinental tickets plus UA credit plus 100,000 mile bonus on UA for flying all Star members!

my all time big five in chronological order:

88 triple miles, what started it all for me

Chart House RTW promo (see previous post) (1996)

SAS Fly 5 combined with UA 100K promo (1998)

Latin Pass Million Mile (a nice even number!) (2000)

KLM status match/mileage match (2002)

some aren't awards per se but these are the ones I remember (there have been some great nonflying deals (Kelloggs, ValueMags, et al) but I see those in a different category