Wentzville is one of those small cities that you've probably never heard of but would certainly enjoy. I moved here a year ago for work and quickly fell in love with the city. It's close enough to St. Louis that you have all the opportunities of a major city, but it's just far away enough to feel very relaxed and comfortable.
Living in Wentzville has a lot of opportunities for work. There seem to be a decent amount of younger professionals in the area, especially ones that are involved in technology. The jobs here pay pretty well and the apartments aren't too expensive, so you'll be able to live very comfortably.
For me, the best area in Wentzville is around Heartland Park. I love to bring my dog there when the sun is out. It's incredibly relaxing and also close to Walmart if you have any shopping to get done. Overall, it's a good choice if you're looking for an affordable city in which to live and do business.