I also vote Jasper, but I work on Heights and The Monorail weekly. (I am not at a billion Real Estate Value yet) I just find I max out on Glass pretty quickly, whereas, since Jasper can get you 2 pills for the same price as Hibbert/Wiggy/Marge/Cletus/Smithers's 1 pill, I find myself just letting Jasper up my Pill total and only using the others if there's something pressing. (like the latest Smithers/Burns/Mountain Lodge s/l) Same with Bumble Bee Man. Since there's not a rush or huge need for trophies, I just let him get the 2 per 20 minutes until I max out and his 1 hour task is visual, so he's basically always on Standby.
And since I had Jasper's Tap ball skin and Stonecutter's skin in storage, I got to play along those storylines, and they were pretty entertaining. I don't really use his visual tasks a lot but they are pretty hilarious. And Sebastian Cobb, the Monorail dude, uses Jasper's building.
I wasn't really interested in Jasper until Heights launched. Then I was all over that like a cheap suit, and I'm really loving him. (same with Disco Stu & Bumble Bee man) So worth it!