Just had a look through some of the key apps I set up on a fresh install:
1Password. Secure password vault/generator. It's cross-platform, and has the best browser integration I have seen. You can also access your keychain via any regular browser if you quickly need to get a password out of it on a system 1Password is not installed/set up on.
ResophNotes (Win)
nvALT (Mac) Great apps based on
Notational Velocity for taking quick notes and searching through them. Notes are saved as plaintext, which I sync via
Dropbox to access them in text editors on mobile devices.
For gamers with an SSD,
SteamTool is great for moving games to/from a larger storage drive (automatically creates/manages NTFS Junctions) and
SteamCleaner clears out all the unnecessary DirectX installers and other packages that are only run when you first install a game, to save a few hundred MB per game. (it adds up when you have tens or hundreds of games and a small SSD)
Similarly,
Link Shell Extension is useful with an SSD.
WizMouse. Lets you scroll any window under the mouse cursor even if it's not the active window. This is standard behaviour on OS X, and something I really miss when I use Windows. I've tried a few of these utilities, and while I don't like the UI (looks like a shady app, but it's fine) it's the one that worked best in my experience.
dBpoweramp is great if you still have a CD collection to rip. (or still buy CDs)
EAC works, but the interface isn't great, it requires a bit of manual setup, and metadata isn't all that good. dBpoweramp combines a bit-perfect CD-ripper, automatically searches and compares multiple databases for metadata, makes it easy to find good quality cover art, supports just about any format you could think of, has good file renaming/conversion options. Worth spending the money if you have a lot to get through.
I think most of the other apps I run are either going to be very common (things like
7-Zip) or too obscure/specific/complex to set up to be worth mentioning. (e.g.
MPC-HC+
madVR+
LAV Filters+
ReClock combination for media playback)