adobe flash is the only way to go!
you need to pay a bit for it though.
armor games only accepts .swf files... a file that only adobe flash can export.
if you just want to have some fun, try unity 3d, it's free but AG won't accept games from it
If you want to make quality flash games, it won't be worth the time or effort unless you have Adobe Flash CS4 or CS5. If you're a student, you can get a discount from their website I believe.
