I have cats so Sugar gliders are to small and I hear they bite a lot. I am looking to keep my critter close to cat size to eliminate some prey issues, although my cats don't seem to have any prey issues, lol they don't hunt, they just look pretty.
Don't know much about chinchilla's but also have been told they are biters as well. Of course I have no first hand experience with either so these could be myths.
I've had sugar gliders. They were super cute and most of them didn't bite me (only one of them did), but they were stinky. I've also had some experience with chinchillas, and I've never been bit. They seem to me to be very active. They also bark (as do sugar gliders), sometimes at night. When I worked at a pet store, a customer bought a chinchilla and brought it back the next day because of the barking. I, myself, love the barking, both from the chinchillas and sugar gliders. The chinchillas at the store I worked off literally bounced off the walls and were a constant ball of energy.
But guinea pigs...
I've had guinea pigs for more of my life than I haven't had them. They are sweet, docile, hilarious, and adorable little critters. They do need a cage bigger than most of what you will be able to find at a store, but it is fairly easy and affordable to make one. They also make the cutest noises. I am greeted several times a day with a chorus of wheeeeek-wheeeek-wheeeeek, especially when they want food or hear a plastic bag. The do best kept in small groups (I have three). Each guinea pig has a different personality--mine range from "I'd rather you left me alone," to "Okay, fine, I will let you hold me and pet me, but I must remember to look like you're annoying me even if I like it," to "OMG! Give me attention NOW!"
Guinea pigs rarely bite, and only if you do something to make them mad (as in nail clipping time). They are also pretty active, especially when young. My older two have mellowed out, but my baby is very active. Also, Kacy mentioned that chinchillas are prone to heat stroke, so are guinea pigs. Not as much as chins, but they are still vulnerable to it.