Here’s a list of my favorite Mac applications that do not come with the Mac. Many of them are freeware or shareware.

Firefox
This one is maybe too obvious to include. However, this open source browser is a must for any Mac user. Many people are shocked when I tell them I much prefer Safari. However, you do Firefox for those times when Safari doesn’t work quite right.

Mouseposé
Mouseposé puts a spotlight around your mouse’s cursor and (if you wish) can display the keystrokes you’re pushing as well. This is incredibly useful when doing software demonstrations as it allows audiences to easily follow your cursor and know what you’re doing. It can also be useful for the visually impaired to find their cursor more easily.

Update: If you don’t need the computer to display your keystrokes, then here’s a free option, Mouse Locator:

WireTap Pro
This program allows you to grab and record software from any application or your entire system. I use this for time shifting streaming audio and video, converting DVD footage into audio tracks.

HandBrake
Whenever I want to add DVD footage onto my iPod this is my tool of choice.

TweetDeck
For Twitter users, TweetDeck has made me a born-again Twitter user. I had lost interest in Twitter until I discovered TweetDeck. It allows me to create groups of those I’m following so that I am sure not to miss the few people/organizations I’m most interested in following. By separating out a few tweets, it also makes it easier to follow the larger group. I love this program.

Doug’s AppleScripts
These are not applications but scripts that increase the functionality of iTunes. There are scripts to copy files off of your iPod, automatically play preview of songs in the iTunes store, corral dead audio tracks, corral one-hit wonders, convert video types and hundreds of other things. These are all free, donations accepted.

DataGuardian
I’m not sure if this is the best of its kind but everyone needs a program to keep track of multiple passwords. This is the one I use to store passwords and serial numbers so I never lose them.

Skitch
From the makers of ComicLife (another favorite app) this program/service allows you to take screen captures and instantly share them on the web. You don’t know that you need this until you use it. Now it’s indispensable to me. All bloggers should have this. It takes a 5 step process and makes it a 2 step process.

For laptops

Hotspot Shield is free and creates a Virtual Private Network when you are browsing public Wi-Fi networks.  In English, this encrypts your transmissions so that you won’t be hacked when you’re on a wireless network used by other people.  Since it’s free, this app displays ads when you use it but you can easily turn it off when you don’t need it.  I think it’s absolutely worth it.

And some intriguing apps I haven’t used  yet:

1Password
Perhaps better password management than my recommendation but also more expensive. It not only remembers and generates passwords, it automatically fills them in.

iAnti-Virus
Free program to identify spyware and malware on your Mac.  I haven’t found any yet.

NetNewsWire
Free RSS reader that syncs between machines.

For more great applications, see this month’s Macworld cover story “56 Must Have Apps” (not available online).

What are your favorite app add-ons?