I think 8 grills is a great start! Just joking, but you do need different grills for different things. Most kitchens have several appliances to cook different ways. Microwaves, ovens, stove, toaster, crock pot, etc. Your outdoor kitchen deserves as much attention as well.
The grills I have collected are vintage and mostly in storage units, garages, sheds, basement, and a few chicken coups. I did have a few dozen in a museum but that exhibit closed last September. I displayed a few of them at bbq contests (Jack Daniels, Memphis May) and trade shows. I’ll dig up a picture and post it. The only time all of them were out was for the Guinness Book of World Records certification. It’s hard to have a favorite because they all are a bit unique and all with different stories. If you go to Meatheads webpage Amazing Ribs and look under the tab of bbq history you can see a few there. Hopefully one day Chris Lilly from Big Bob Gibson BBQ in Decatur AL will house the Barbecue Nation exhibit that was on display in Atlanta History Center last year.