What are y'all's favorite? I'm trying to decide what to try next. Also what might do good in hot and humid climates such as Houston? Thanks in advance for any responses.

I grow many varieties from MP. 

De La Reina is the best taste and fast grow,

resistant for hot and humid climates. 

Martinenca Rimada

I only tasted Bordissot Negra so far. Pretty good.

Hi,
In Zone9, I would first try all the "col de dames" (noir, blanc, gris) and bourgeassotte ( noir , blanc) - MP has them, and others have them too on your side of the big swimming pool.
For MP, I don't know if there are already lots of his cultivars on your side of the pond - He hsa so many listed - some he even reports them as not desirable, since he wants to preserve diversity.
But normally, you can legally buy yourself directly from his website.
You could then yourself become a source for those varieties on your side of the pond. That would be a nice project ! But a collector thing ! Just be careful, he has lots of smyrnas too ... Because he is equipped for them ... ! 
Keep them well labeled.

If you have the wasp in your area, you would be looking at smyrna types and brag here on the forum about them :) .
By the way, I don't have any from MP :( ... You have a Longue d'aout ? You need one ! What do you already have in the collection ? Lots of ?