I’ve never had a rice cooker, but that would definitely be nice. I don’t put it in the must-haves, because I can just cook rice in a big pot on the stove. Easy enough for me.
I don’t have any must-haves to add, but I’ll share what I use the most.
Toaster oven: this thing is gold because it’s so versatile. It’s so much faster than an oven because it’s smaller. And you can do a handful of things with it. You can use it for any normal oven functions, and it also replaces your toaster, so the space it takes on a counter can be justified. You can’t cook a ton of food on it, but I can do like 4 or 5 chicken breasts or salmon filets a time in mine, and because it’s so fast and user friendly, I could do a couple runs in a row like that and be done cooking quickly. Good for vegetables too.
I use my green egg smoker for most of my meat. Clearly a 700 dollar grill is not a necessity. But it sure is nice. All my red meat goes on this, and I can cook about 8 burgers at a time on it, or a handful of steaks, etc. salmon and chicken are great on it too. I think things I cook on here reheat better than other cooking methods, usually.
pwnisher’s foreman grill suggestion reminds me of college. That’s how I cooked everything when I was 20. If space and money are limited, or if you don’t have outdoor space for a grill of any kind, that’s a solid option.