vBulletin includes a default "Forum Block" that does that, I do believe.
Follow:
AdminCP -> Forums & Moderators -> Forum Blocks Manager
You should see a forum block labeled "Forum Threads" which you can configure to your liking.
If you want a product that shows the most recent posts in the recently updated threads, with BBCodes parsed, you might want to consdier this product:
Forum Sideblock - Recent Posts (with BBCodes parsed) [v1.3]