This is what I have in 6 qt., and I really love it. I only cook for myself and my boyfriend, but extra room in the crockpot doesn't hurt- and honestly it doesn't seem too big. I got my mom the crockpot linked by Sethomatic and she loves it! (It was $17 on Black Friday).

https://www.amazon.com/Hamilton-Beach-33473-Programmable-7-Quart/dp/B01CY9LPBC/ref=sr_1_1?srs=2529533011&ie=UTF8&qid=1484671946&sr=8-1&keywords=slow%2Bcooker&th=1