At the moment there's a piece by David “The Wire” Simon floating around the web which I don't think reflects him at his best, but which does include a good statement of something I agree with:
I'm not a Marxist in the sense that I don't think Marxism has a very specific clinical answer to what ails us economically. I think Marx was a much better diagnostician than he was a clinician. He was good at figuring out what was wrong or what could be wrong with capitalism if it wasn't attended to and much less credible when it comes to how you might solve that.
You know if you've read Capital or if you've got the Cliff Notes, you know that his imaginings of how classical Marxism – of how his logic would work when applied – kind of devolve into such nonsense as the withering away of the state and platitudes like that. But he was really sharp about what goes wrong when capital wins unequivocally, when it gets everything it asks for.