Bison (aka Buffalo) is an excellent source of lean protein that if cooked correctly tastes very similar to beef with a bit more sweetness.
Bison is a good source of protein, iron, vitamin B12, selenium, zinc, phosphorus, vitamin B6, niacin, iron, omega-3 and omega-6 fatty acids while being low in fat. Click here for a nice nutrient comparison chart.
The main problem that most people face when trying bison for the first time is that cook it just like they cook beef. Unfortunately, that is why most people think that bison is dry and chewy. Bison contains a lot less fat than beef causing it to cook faster - so it should be cooked at a lower temperature than beef.
I was browsing my local co-op's blog and found an interesting post with tips and tricks for cooking bison. Check it out here.