Most people with your requirements choose the MX-5 and it's easy to see why. It's great fun to drive, well built and cheap to run. There are also a huge number of MX-5 specialists and a great network of enthusiasts so parts and repairs are affordable. There are also plenty on the used market and for your budget you can get a tidy T-plate MX-5 1.8i with just 44,000 miles on the clock. Another car to consider is the Toyota MR2.