What airline/hotel mile do you consider to be most valuable?

1. One bmi diamond club mile

USA to Europe, First Class, any *Alliance airline, 50,000 miles plus @$700
Worth $3500 to me, or $0.056 per mile

2. One SPG point

USA to London, Upper Class, Virgin Atlantic, 65,000 SPG points = 80,000 VS FlyingClub miles
Worth $2500 to me, or $0.038 per mile

3. One AsiaMile

USA to Europe, First Class, any OneWorld airline, 90,000 miles
Worth $3000 to me, or $0.033
(worth less due to max. one-way distance of 5000 miles)

4. One United MileagePlus mile

USA to Australia, First Class, United Airlines, 120,000 miles
Worth $3500 to me, or $0.029 per mile

To make this fair, you need to pick a "point currency" that is roughly equivalent to one mile of flying or one mile per credit card dollar spend. You should also not judge value based upon "full retail price" and instead consider value to be the savings based upon what you would be willing to spend in cash for the same trip. For example, heavily restricted first class roundtrip to Europe is worth $3500 to me, not $14,000 for the unrestricted, full-fare first class.