First off best comes down to what you want to use it for and personal taste
I can't comment too much on softwoods, as I prefer not to use it
depending where you go, cheapest hardwood is usually idigbo but I hate the stuff, has tendencies to get cross grain shakes and it's awful to work
second cheapest is usually sapele, has a straight grain that is easy to work, but I find the grain a little bland, so I normally use it for external joinery with a paint finish. No reason why you cant make a nice piece with it with the right finish though
Iroko could be another option, has a fairly interesting grain, is ok to work and isn't as expensive as oak. I tend to be wary of using it though as although many Iroko suppliers state that their wood comes from sustainable sources, this is not necessarily the case.
Best (IMO) is euro oak, abw and maple, they tend to be a bit dearer but are long time favourites of mine