I think a lot depends on what language(s) you're trying to work with, and, more importantly, why you're not clicking with those other tutorials. Heck, it may just be that the language your writing in or tools you're using are just wrong for you. Me (for example)? I have a real blind spot when it comes to Java - i've just never been comfortable with it. But most other languages have come (relatively) easy.

But, in answer to your original question, I've been very impressed with the exercises up at Coding Bat.