Best paper trading simulators

A few years ago, I jumped in without much practice and got burned pretty fast. Now I’m looking to do it right — start with some paper trading to test strategies and build confidence. Thing is, there are so many platforms out there, and it's hard to know which ones are actually helpful and which are just basic simulators with fake market conditions. If anyone has used a paper trading simulator that felt realistic and helped you learn, I’d love some suggestions.