The folks at the Grand OGL Wiki are doing reviews these days, including 4th Edition reviews. This review of Wrath of the River King by Sean Holland caught my eye.
While I admit that I have not looked at all of the 4th edition adventure available, this strikes me as the single best one I have seen. Wrath of the River King uses the D&D 4th edition rules to their best advantage making sure to make every encounter interesting and challenging.
You can read the whole thing. The adventure is still available to patrons of Halls of the Mountain King.