For non-hybrid vehicles, the Ultragauge looks to be a strong up-and-comer.
And at it's price point and better gauge readability, it might be "the thing."
(It does not have the capability to program hybrid-specific readouts like the
SG's XGauge feature.)
There is discussion of the Ultragauge's pros and cons and photos on cleanmpg.com:
New Ultra-Gauge: First Impressions, Quick Hits, and quick comparisons to ScanGauge
A great gift idea to get family, etc into a gas-saving frame of mind.