Just posting for completeness’ sake.
Citi / AAdvantage Platinum Select MasterCard – 60,000 miles after $3,000 spend in 3 months
CitiBusiness / AAdvantage Platinum Select World MasterCard – 60,000 miles after $3,000 spend in 3 months
American Express Starwood Preferred Guest Business Credit Card – 25,000 points after $6,000 spend in 3 months + 10,000 extra points after additional $4,000 spend in 6 months (so $10,000 spend total)
The number of miles and points offered by these cards are relatively good, but personally I’ve been finding AAdvantage miles more difficult to use lately and have thus amassed a pretty large stockpile of them. As for the SPG offer, their points are great, but $10,000 spend is a bit much, especially now that American Express is looking out for manufactured spending techniques and may potentially deny the bonus if you use MS to meet the spend requirement.
Anyway, these offers are still worth doing if you’re looking for more AAdvantage miles or if you can meet the SPG card’s $10,000 spending requirement easily.