On the rare occasion I use them, I opt for the Truvia brand, which is a combination of stevia and erythritol, tastes almost like sugar and does not spike me. Sometimes I like a half teaspoonful in coffee with cream, and it's great for baking. I used Truvia in a fabulous low-carb cheesecake I made at Christmas, which was devoured by sugar lovers who would normally turn their noses up at Truvia in tea or coffee.
Some sweeteners - and granulated Splenda is a good/bad example - have maltodextrin mixed in with them. Maltodextrin is a fancy word for sugar. It's worth looking up all the other fancy names for sugar too before going on a sweetener quest.