Lots of great suggestions. I didn't see lithium cordless drill/driver. I think this is my most used tool these days. Get a large assortment of bits and a flex extension. With this tool you can handle all manner of screws, torx bits, allen, hex, whatever. Some guys like the big manly (heavy) 18v max torque guns. I have one but find myself mostly use a smaller lightweight Makita that I can get in to all sorts of tight places or work overhead for extended periods without fatigue.
https://www.google.com/shopping/product/14540173231914253621?lsf=seller:1135568,store:3393 253856512187126&prds=oid:3925461602938697427&q=cordless+flex+adapter&hl=en&ei=5nEnWb7oNOiX0wKClrDAAg&lsft=gclid:CPLwyZKijNQCFYSTfgodwmQDRQ
Another useful tool for old cars: A 1/2" breaker bar and 4' x1" galvanized pipe as a helper. Lots of old rusted bolts that respond well to a little leverage.