I've never used Blitz Basic, but I've used some other BASIC dialects and if it's anything like those it should be pretty good. The thing about BASIC is that it gives you ease of use while simultaeneously allowing you to accomplish advanced stuff that you could never do in a click-type tool. You'd never see yourself making an RPG in TGF, it'd be way too difficult and tedious, and it's near impossible. If you wanted to try in RPGMaker, you'd be limited to a very Final Fantasy-like RPG.
If you get something like Blitz Basic, you can make just about anything you can figure out how to code. This means you could make an RPG in the style of say, Mario & Luigi rather than Final Fantasy, or you can make just a platformer, or something else even. There's virtually no limits.
Now, Blitz Basic came in two varieties the last time I checked: BlitzMax, and Blitz3d. BlitzMax can make only 2D games, while Blitz3D is centered more around 3D ones (though it still can make 2D games). BlitzMax actually has a one-up on Blitz3D though--It can make games for Linux and Mac, not just Windows, while Blitz3D is just for Windows.
As for learning the BASIC language, search for a BlitzMAX tutorial. There should be one around that'll give you a rundown of the Blitz dialect (every dialect of BASIC is a bit different).
Don't rule out other BASIC compilers though. There's also DarkBASIC. DarkBASIC Classic is mainly for 3D games, but can make 2D games with some hard work. It has a 3D object collision problem, but there's a DLL or two out there that fixes that. Then there's DarkBASIC Pro, which has a better GUI, better 3D collision and more advanced features, along with better 2D support than it's predecessor. It supports DirectX 9, where Classic only supports DX 7.
Then there's PlayBASIC, a BASIC language solely for making 2D games, but which is the easiest to use from all that I've heard. It has commands for advanced 2D stuff that you'd have to code yourself in other BASIC dialects, such as map scrolling. It also strains your computer much less than any of the others.
Some links:
DarkBASIC ProPlayBASICBlitz BasicCheck 'em all out and see which one is best for you.
This post has been edited by Banjzooie on Jun 1 2006, 02:52 PM