If you still like this old game. You can buy an HD version on Steam. Afterwards you can get a patch for it to play on voobly.com
Voobly is pretty much where most people from all over the world play and some of the greats. So I would recommend playing there if you want a challenge.
Saw that this was a place for AoE, but saw no posts about it. So I thought I would add this in. I knew a few that are very into the AoC community on Voobly.