First: budget. What do you want to pay? Do you already have a camera, or are you wanting to buy one?
Second: Webcam or DSLR? "Camera" is a generic term, so in stop-motion land, we divide this into two categories: Webcam and DSLR. The Logitech c920 is an excellent webcam. DSLRs will take a bit more deduction to figure out which is best.
After those are answered we'll be able to help you more.
Keep in mind there are pros and cons to both webcams and DSLRs.
DSLRs are the best for serious stop-mo, but are a huge investment beyond just the camera. There's tripod, software, lenses, etc etc. Once you start, you can't stop. Yes, DSLRs are larger and heavier than webcams, but that's no con in my book. You just need to know how to handle them. It's far less likely you're going to set your DSLR on a desk like you would a webcam, so you need more space for the tripod and stuff.
Webcams are small and compact. They have somewhat good quality (like I said, the c920 is THE BEST). However, your lighting has to work with webcams because of their censors, they hate low-light. There's more software available for webcams, unlike DSLRs, so that's definitely a pro for webcams.
But please please PLEASE do NOT get a point-and-shoot camera (like a Canon PowerShot, a Nikon compact, or something like that). They usually do NOT have manual settings, most software don't support them, and they (yet again) aren't great for setting on a table.
If you're leaning toward DSLR, please get a Canon. Nikon cameras (at least, the lower end ones which don't cost thousands of dollars) have lots of issues with lenses and software connection. Canons are pretty much THE camera when it comes to stop-motion. As the the Canon XS, it looks a bit old, so you'll have to check with your software to see if it works with the camera. Most DSLRs have good quality, even if they are a bit older, but of course, the most recent ones (generally speaking) have the best censors, thus are better. I know that I can recommend the SL1, and others have recommended the T2i.
YouTube • Website"Whatever you do, do all to the glory of God." - 1 Corinthians 10:31b