The next best thing after that is MJPEG compression, closely following by DV compression; both of these give better compression (smaller file sizes) than huffyuv but are lossy.
MPEG-2 on-the-fly compression is really for convenience only, in a DVD recorder or a PC used as a PVR (when you want to store small capture files for immediate playback).
Best results are obtained by capturing lossless video, editing/processing the capture file, then encoding to MPEG-2 using a VBR multi-pass encode.