Hybrid, touring, or road bike for new commuter?
8 miles each way is a reasonable commute.  

In the city a pure road bike is not as stable.  

You should test both flat and drop bars to see which is more comfortable for you.  Drop are a little more efficient but that is not a long commute.  For an uphill I think flat bars are fine.  

A full touring bike is probably more than you need unless you are looking to mount racks and also using it for longer rides.  And you probably don't want rack or fenders loading it on and off bus and trains. 

Look for mid sized tires (like 32mm).  

A light bike is also nice for getting it on an off bus racks.

The also have styles of bikes called urban or city.    

Even a mountain bike with street tires would work.  Not a first choice but if you found a good deal used.  

A local bike store (LBS) will help you out with fit and selection. You can get some decent new bikes for $600.

If you are on a budget then CL but be careful.    

I like a cyclocross bike fit with touring tires for commuting but maybe not the optimal for you.