Hiya, I use Maya for most everything on the visuals and it's written in Renpy. The models are imported from Daz Studio and then modified for my purposes (hair, modeling, soft-body, etc).
As my wife mentioned, though, this decision was made years ago when I first started learning 3d applications. These days I would recommend Blender for someone that isn't already working in a different program. Maya does some things really well, but it's also mired in professional elitism (the community is hit and miss when it comes to support), costs a lot of money, and has a slow development cycle (much like I do). On the other hand, Blender is free, community-focused, and has a lot of the same tools as Maya. Basically, 5 years ago Blender was meh, 3 years ago Blender was pretty good but not really professional standard, last year Blender started seeing some features that were as good as anyone else, and right now Blender has progressed to the point that a professional studio may seriously consider them to replace Maya or C4D.
And of course, Daz is really good for individual characters (especially if you want realistic models). I chose to leave that environment because I didn't like the lack of freedom in scenery and simulations (I think they've gotten a little better at hair sims, though). It's also much more difficult to get a solid toony look in Daz (though not entirely impossible), since you're relying on shader packs instead of the actual nitty-gritty shader nodes you'll find in Blender or Maya.