How much memory does each game on xbox take?

I'm looking into buying the new xbox slim and there's the 4 gb and the 250 gb. I really don't think I need a 250 gb hard drive. I'm not going to download any movies or anything, just going to save game progress. So I think the 4 gb is good but do xbox games take alot of space? On average how much space does each game need?How much memory does each game on xbox take?If you are only saving game progress, you should be fine, but if you ever want to download from Live, you will be screwed. I've downloaded the expansions for borderlands and am almost full. I am going to get the 250GB as soon as this one craps out, which will probably be soon.