I’m a fan of undersized throws.
What would you get?
Learning toward the Dietz right now…
There are a lot of very good undersized yoyos on the market. Dietz, entheos, wool marmot, or if you can find one, the undersized noctu.
Supra for sure.
Supra, dietz, messiah are all equally as awesome as it gets
If you are looking for something cheaper that is Bi-metal, the hitman pro is an awesome choice. Super smooth and stable, great weight distribution, fun stuff.
J
Supra, Wooly Marmot, markmont.next, P2, and Messiah for me. 
SPYY Supra, One Drop Dietz with CODE 1 SE’s, Yuuksta, Wooly Mar/Mark:mot/mont, ONEstar (OD and General Yo)
For me, it’s the RT, Messiah, Y Factor and the Wooly Marmot.
For me, I think Gnarwal, Hitman Pro, XCon Pro, Wooly Marmot, Dietz. Not necessarily in that order. I’ve got stuff smaller too.
But, since we brought up the whole “best” thing:
It’s all about preferences.
Yeah, these are just our preferences.
So keep in mind that it’s up to you to decide what you like best, but I suggest what’s listed here. 
I like my Dietz, but I don’t play fast enough for it. I’ve really come to like the Bape.2, especially after curing its hunger for string! Super smooth and plays at whatever speed I can manage.
Personally I love the dietz as well and it is still readily available but if you can find a Hatrick, that’s my all-time favorite. The supra and entheos are nice as well as the darkstar. If you can afford it the bapezilla 2 is also an awesome throw. Happy Hunting!