I agree with NLXTACY on Solidworks, but it can be quite pricey if you are only doing 2D drawings. I'll also recommend their DraftSight. It's a greal alt for 2D needs. We looked at moving over from AutoDesk products, but most of our R&D guys are pretty set in their ways (imagine that.)
I agree on the better software. Growing up I used AutoCad. Using SolidWorks now; but is a bit overwhelming. I have DraftSight and works well for what it is. Most the crap we shuffle around clients for presentations and whatnot is done in Visio. I suppose any would get the job done with a good stencil set.