My wife and I saw Polar Express in the Palm Springs IMAX shortly after it came out a few years back. It was the best 3-D experience either of us have had. It was simply amazing.
The story wasn’t as strong as I would have liked, but it was an overall positive experince. The graphics were incredible.
I saw Beowulf in 3D. Like you said, the story wasn’t all that great, but I thought the effects were spectacular.