I have a very cheap mattress - came with the bedstead, and 4 years later, it's decidedly knackered...!
DH and I are arguing over 2 mattresses in particular. (But I'm open to other suggestions!! )
One is an Ikea mattress, the favang, and the other is a Bensons one, called Sleep to Live.
I like the Sleep to Live - it's got 2 different firmnesses (is that a word?!), so you do an assessment, and it's profiled for each sleeper. I like this one as I need a firmer mattress than DH due to back issues. They are expensive, but for the basic one, my friend (who works at Bensons) can sell me one for £665 (normally £700) or the next one up which is thicker, for £945 (normally £1050). Also, it's guaranteed for 10 years. (here's a link)
DH likes the Ikea one because it's cheaper,(£159) but I understand we'd have to change our bedstead for it. Thing is, I really don't like their bedsteads - we have a lovely wrought metal sprung one, yes it was cheap, but I like it!
At the moment, we have a sprung mattress, but I think it's pretty safe to say we'll need to change to some form of memory foam thingy.
What would you suggest/recommend?