My dad has done so much for me in my life.  The thing he seems to appreciate more than anything is good tools.  The last thing got him was a Milwaukee brushless cordless drill and he seemed extremely happy about it.

Anyways he has a magnetic screwdriver he says is the best he has ever had.  Just a simple driver that takes different bits.  He left it on top of a water heater and the handle is all melted and distorted.  He says nothing else will hold bits like it does.  I'd like to get him another one that holds bits like no other.  Any recommendations?

Snap on makes a racheting one that is solid . I have owned mine for 20 years .

Brownells MagnaTip.

Or Harbor Freight - just test fit to find the one on the tight side of the off-spec manufacturing 

im usually more worried about the screw holding on than the bit itself. Some designs have built in retention, that's why that groove is on the side of the bits.

https://www.amazon.com/dp/B002NI1LZK?tag=vglnk-c102-20

This!

Brownells has nice tools.

The Snap-On ratcheting soft grip screwdriver is king. Seriously, it's got really fine teeth in the gear and the handle is ergonomic with room for a few bits, the shafts can also be interchanged. Felo (German made) also has a great screwdriver. I have two of them, one with a magazine in the handle for bits the other without. Snap-On one is awesome though. Snap-On screwdriver

~$11 Amazon

Great driver with a very strong magnet. I absolutely love it.

Lifetime warranty and made in Germany.