For side sleeper, the real game-changer is finding a mattress that gives you that sweet spot between pressure relief (especially around your shoulders and hips) and proper spine alignment if its too soft you'll sink in lol and if its too firm your body feels crunched. Cooling features are a big plus too, since foam tends to trap heat. Out of all the ones floating around, smth like this egohome one is acc a solid option. It’s got that copper gel-infused memory foam for cooling, plus individually wrapped pocket coils that adjust to your curves and absorb motion. More on reddit.com

If you live in America, Costco and Sam’s club provide amazing value in mattresses. We went to a mattress store, decided we wanted to buy a hybrid mattress after trying out a variety of models. Then we asked them what makes a good mattress, and they basically answered that the number of coils. We found a king size mattress on Sam’s Club for like $500, and asked them if there was any reason to buy the $2k mattresses from their store. They said there was no reason, so we went with Sam’s Club, and have been very happy since. More on reddit.com

I totally recommend Avocado Mattresses. They have quality materials and killer springs! More on reddit.com

I have been to the local stores and have not yet found an "old school" innerspring mattress that is plush enough for me and doesn't have me sinking into foam. I get shoulder bursitis flares so often have to sleep on back but I much prefer side sleeping when I can. More on reddit.com