Thanks for all your feedback. I'll definitely check out these tools that you have suggested.

No to forget there is MOAI, which is also cross-platform http://getmoai.com/ but they say, its for pro game developers, so if your just starting out you might find it a bit complex.

I have also used Cocos2d-x, but I dont like they way things are done in Cococs2d-x, but its free and cross-platform, so its a good option

Has anyone used GameMaker to make iOS or Android games. They have the ability to port to those devices, but haven't seen any opinions on this.

Well, since Cocos2d-x and Corona have already been mentioned, you should also have a look at Marmalade.

I am currently trying out Corona SDK and like the fact that it can be used with Lua.