They're controversial here but I like working with Market Force, they have a handful of clients I like to shop, their reports are generally very easy to fill out and the self-reschedule option is nice when needed. Plus they reimburse bridge tolls, which opens up the Bronx/Westchester/southwest Connecticut as shop areas for me (I'm on western Long Island). Most of the other companies I work with don't reimburse, so if I want to venture off LI for them I have to bundle it with a MF shop.
BARE has some good schedulers, and if you wait them out the fees aren't bad.
Ipsos pays fast. I tend to find more shops that are interesting to me on the Sassie side than on Shopmetrics.
I always liked working for Intellishop, but sadly their lineup of appealing shops in my area has plummeted since Covid. They now only offer one that I will still do. Oh how I do miss their bartender compliance shop for the black and yellow sports restaurant.
I have fun checking in on the Field Agent app every day but only sporadically work for them because the pay is awful. If you keep a sharp eye out, though, once in a while you'll find a shop down the street that's so easy that it's worth it even with the low pay. (Buy a can of beer, take a picture of it, write 3 sentences about it, get the tiny fee plus reimbursement lol.)