I'm a fan of Haydn sonatas... But there are so many good ones to choose from! Give some help here. Prefer minor or major mood? Fun, energetic, peaceful, intense? I'm thinkin' that if you're at the mid-high level Beethoven level, most Haydn shouldn't be too much of a challenge. Hard for me to say though, I'm more in the easier-Haydn level of playing.
Off the top of my head, here's two suggestions:
Sonata in D, hobXVI:37 - first mvmnt's pretty bouncy and fun. Second movement's my favorite, an intense, moody, thick textured Largo sostenuto. 3rd mvmnt's is Presto ma non troppo, a good balance between cheery peaceful and drama, by my tastes. ~11 mins.
Sonata in A, hobXVI:30 - two movements. First movement has some pretty rapid figurations, tricky articulation. Good variety of themes, keeps a good forward driving motion. It's the development I love, very interesting. He doesn't repeat the development, but it's so good leaves ya wanting more, then wraps it up with a completely different adagio, which I love. Second movement is a Tempo de minuetto set of variations. Pretty calm, entertaining. Not intense, just chilled. Some of the variations sound like a lot of fun to play. ~13 mins.