Do you need a badass capture box? AVerMedia's ExtremeCap U3 looks to fit the bill with its uncompressed 1080p 60fps video capture. They sent over info on their new USB 3.0 box that lets you not only capture, but also stream at 1080p 60fps via HDMI or component. I wants it.
If you're into producing video from your gameplay, know that the U3 comes with plug-ins for Premiere Pro CS6 and Sony Vegas. There's even a USB 3.0 Diagnosis Tool to ensure top performance. Check out their product page here.
I don't know that it works for Mac, though. We're working to find that out. We're also checking on availability.
What do you use for capture?