[stomachmonkey]

Disk utility is fine for drive tasks.

Not much else you need to do as the OS handle fragmentation for you.

For command line stuff I prefer iTerm over the stock terminal

Grab a couple of compression apps to deal with stuff like rar files. 7zx, keka, unrarx,

Clamavx is handy but recently went from open source to paid.

Spamsieve for Bayesian mail filtering, paid app but worth every penny.