I agree you need to do some homework and find answers that pertain to your situation, instead of asking vague general questions and hoping to be spoonfed the best answer....SD is for lazy, greedy, high school dropouts, who are looking for the best deals with the least amount of work or effort.
FT is a different animal, it is a resource for those willing to READ, SEARCH, and READ SOME MORE. 90% of the answers to any airline or hotel program are already discussed.

In this case I suggest you start by reading the FF program charts from each of the companies sites...go to CO and look at cost of upgrades vs business or first costs in points...also look at what it costs on their available partners that fly to the cities your interested in....do that for AA/BA as well. you should have read everything about the programs you have points in from their websites comprehensive info...yes it's boring, but you need to know in order to use their points wisely....then go to the programs threads here in FT.
show some effort.