Baseball is more popular.
I think Skateboarding is more popular.
Skateboarding is getting more and more popular everyday so the answer is today
Basketball is a more widely played sport but I guess its whoever you talk to Skateboarding is much more popular than basketball because I ask people what is your favorite sport between basketball or skateboarding and they say skateboarding.
Vert skateboarding was much more popular in the early through late eighties until street skateboarding began to rise in popularity in the early nineties. Skateboarding is much more popular presently than it was in the legacy years of the seventies and eighties. Both vert and street skating have a healthy following to date.
Skateboarding is popular in most countries. That's why they have different contests for world-wide skaters. Skateboarding is most popular in the United States. Specifically, Skateboarding is most popular in California. California has many skateboading parks and lots of skateboarding stores. If you wanted to skateboard I would recommend California.
Both - skateboarding is popular with children, and so too are skateboarding competitions.