For two years, I've stayed in a pretty crappy hotel when I'm on business in Osage Beach - only because it's walking distance to Domenico's.
The food is absolutely awesome, large portions, great service. If you want a high-end experience, there's plenty of pricey dishes on the menu. However, there are also lots of great meals in the $10 - $15 range as well. Full bar with liquor, beer, and of course a tremendous wine list.
If you're at the Lake of the Ozarks, you need to stop and try Domenico's at least once.