i say the ONE. you guys? (remember, i know there is no best, what do you THINK is the best)
yyj classic 
ONE
Butterfly xt(but I havent tried Classic yet).
Classic and it’s not close
yyj classic
I’d say a whip over a one. but both of them are too light. Even the other yyf yoyo they were giving out for the east coast tour is too light.
One and Butterfly XT are too light. Also, when I had a One, it was never responsive with the slim bearing. This was before I’d learned how to bind, so this resulted in me not liking it. The Classic’s weight and rubber o-rings make it truly responsive (with the slim bearing), making it easy for those new to yoyoing to start throwing right away.
Bought a Classic. Can’t beat it for ten bucks.
I’m waiting to get some Classics.
Until then:
Wasn’t impressed by the Fast 201 even for noobs.
ONE, with 2 bearings. It can take you a LONG way!
Duncan Butterfly XT? No. Under $10? Yes it is, but when you clean the bearing to play it unresponsive, it’s too light. I’m buying a second to send off for weight ring mods.
ProZ: Depending where you get it, it may or may not be under $10. I paid $8 each. Loads of fun with a transforming yoyo designed for modification. Change out metal spacers and bearings… loads of options!
Freakhand: Great 5A starter set, and on sale, $9.99 at a big box brick and mortar national store.
I’ve got high hopes for the Classic.
For unresponsive play I like the Whip. The Classic plays great for responsive and I like the weight, but after I put in an unresponsive bearing I liked the Whip a little better. Both great choices for 10 bucks, though.