What is the best first JDM car to buy?

The Mazda Miata (NA/NB) is the undisputed best first JDM car — affordable ($5-12K), reliable, fun to drive, endless aftermarket support, and cheap to maintain and insure. Honda Civic (EG/EK) and Integra are also excellent entry points. Avoid starting with a turbo car or a Skyline — the maintenance costs and temptation to modify beyond your skill level catch many beginners off-guard.