For most things I do with ground venison, straight deer. I do chilis, taco meat, meatloaf, shepherds pie, meatballs, sloppy joes, etc. It's better than beef for a lot of that stuff because you don't have to drain any fat. Some of those things such as meatloaf and meatballs, if they need a little fat I'll mix in bacon drippings.
For any kind of sausauge I mix in about 20% pork backfat or just go half and half with a fatty pork butt. I don't really notice a difference between the two, so I usually do the 50/50 method just to bulk up the yield a little more. And the pork butt is easier to find.
When I want a good burger I buy 80/20 beef or grind my own chuck roast. I've had some okayish venison burgers and I'll still make a couple every fall when I have fresh venison to work with. But there are better uses for deer meat and beef just makes a much better burger.
Also I don't grind much when I butcher anymore. I cube the meat, vacuum seal the cubed meat in 1 lb packages, then I can do what I want with it and when I grind it months later it stays fresher that way. This time of year is when I am clearing freezer space to get ready for the upcoming season so I start making a lot of "processed foods". I made 5 lbs of venison Cincinnati chili and 5 lbs of venison/pork gyro meat over the weekend. Then I portion those out and freeze them in individual and family servings. I still have a lot of shanks left from last year, so sometime soon I'll do a big batch of shredded meat for tacos/enchiladas, etc that freeze well vac sealed. Stuff like that makes great quick meals for home and deer camp when I get home from hunting late and want to eat well without a big to do.