How much ram do you recommend for minecraft?
Depends what you're doing.
For normal playing, with no mods, 1gb is generally enough.
For playing with large scale redstone/many entities/Amplified world/etc. go for 2-4gb
For playing things like Feed The Beast, or other large scale modpacks, I'd go for 4.
But as I said, it all depends on your computer, where/what you're doing, what texture pack you're using, how many people are near you and more.