And ben ji, half of your examples aren't that great.
The US did have a great ally in the Shah's Iran. Was he a rough rider? Yes, but did Iran mostly prosper? Well, yes, kinda. Surely a crap load better than the Islamist regime.
The Muj and Iraqi in the 80s are clearly mistakes which were more pragmatic mistakes rather than pronounced failures in picking allies. By that I mean we failed totally in character judgement, but it was a relationship of pragmatism IMO, rather than a failure in picking a true ally.
The Libyan rebels is debatable since we didn't arm them or help them out as much as many other western nations did (France). Its a little too convenient to lay that America's doorstep instead of NATO's or western Europe.
And the test isn't really finished for Syria. If we have worked with the moderate FSA earlier the entire region would look much different than it does today. It just shows you how many times the US has failed to pick the right groups early and support them with the correct amount of enthusiasm.