Idk if it’s “classic” or iconic enough, but I have to throw the YYF CzechPoint Pivot in the ring.
If you really want to know why, check the link. In short, it’s easily in my top 3 favorites I’ve ever thrown, even over many expensive bimetals. Hands down the best performing & all-around monometal I’ve tried.
You should be able to pick one up on the BST for around $30-35.
Edit: thinking about it, the Yoyoball Hendiatris is more underrated and deserving of this slot. Such a unique yoyo, and not even a little gimicky. Appreciation post coming in the next few weeks.