One question we get asked a lot is to compare memory foam mattresses vs latex mattresses. Perhaps that is because in online ratings, as analyzed by SleepLikeTheDead, memory foam mattresses and latex mattresses get the highest ratings for comfort -- both much higher overall ratings than standard innerspring.
But while latex and memory foam share the top spot in terms of comfort, they couldn't be more different in terms of their overall feel.
Memory foam, due to its unique cell structure, has a conforming feel and you sink into it when you lie on the bed. In contrast, latex provides a firm, bouncy feel that gives a lot of cushion due to the density and elasticity of latex.
I should say here that when I refer to latex mattress, I'm exclusively talking about an all natural latex mattress. I find that synthetic latex just doesn't have the same feel, not cushion, that natural latex offers. If you would like to find out more of the ins and outs of latex, a good start is this in-depth guide: The All Natural Latex Buyer's Guide (And if you are confused about memory foam, they offer a buying guide on memory foam mattress as well.
The best way to get a feel of whether a memory foam or a latex bed might offer you the best overall comfort is to try out a few at a local store. While spending a few minutes on a bed won't necessarily tell you if it will work for you over time, it should tell you both which feel (memory foam or latex) you prefer, and if either just doesn't work for you at all.
Once you've gotten a feel for which mattress might work best for you, you then might want to consider looking online to find a retailer that would offer you a good money back trial period. That way you can be assured you can try the mattress out yourself for a good period of time, and if it doesn't work out for you, you don't lose hundreds or thousands on a bed that just isn't for you.
Before buying make sure you check out the online reviews, BBB ratings, etc, to make sure you are going with a reputable dealer that will really pay off if you do decide to return it. And pay close attention to the mattresses' product reviews to ensure that that particular mattress offers the feel you are looking for.
Overall, you can't ensure that any particular mattress will be comfortable. But starting with memory foam and latex mattresses gives you a great chance of finding a bed that reviewers overall have found the most comfortable options.