Well, I am not that good player, I think I have a good first serve, a strong forehand but sometimes erratic and a consistent backhand. I don´t get many winners from my backhand but it is a strong weapon in my defense because I can play it really deep and with a lot of bounce, which makes it difficult to attack. My forehand used to be a great weapon, not a really good technical one but I started working on it and now I am thinking more while doing it and sometimes that is just awful.
I already played in grass, clay and hardcourt. I am more used to hardcourt, I think it is the one I am more confortable. Grass is really difficult, the ball doesnt bounce, the slice is a really good weapon there and I am terrible at playing against a player with a good slice. But in other way, i prefer to play more flat so it is a good court for my game but it obviously take more time to get used to.
I remember the first time that I played on clay and I hated it, I made a lot of unforced errors because the points are bigger but in the end I got used to and was playing my normal and enjoying it.
But I would say harcourt.