Do you buy UMD moveis or do you convert your DVDs

I convert avi files to mp4 just to play them on the PSP. But I don't really own a lot of DVDs in my house. I tried converting one once, and it took a really long time. I'd rather just convert avi files.

I get free UMDs from my friend, like all of my friends had a PSP and sold them and could never find there UMDs so they give 'em to me when they find them.