I used Inventor for a while. It was a decent program (a huge leap better than the previous Mechanical Desktop). It all depends on what you need to do. Inventor has a really easy learning curve and handles large assemblies pretty well also. I can't remember Inventor's importing abilities to file types, like lGES, for other programs like FEA packages if you need that functionality. I think the cost for Inventor may be a bit lower than Solidworks too. However, I am not a huge fan of Autodesk. Their version of support is pathetic.
I would lean towards Solidworks if those are your two options. Again, it all depends on what YOU have to do with it. If you are doing basic things and not huge assemblies, etc... I would say let price and ease of use be your guide. Most lower end programs seem to be grabbing features of each other so they are all starting to look alike.