My own personal favorites thus far:
Adium X: A free IM client that's supports AIM, ICQ, MSN, Yahoo!, Rendezvous, Yahoo! Japan, Gadu-Gadu, Jabber, Napster, Lotus Sametime (via the Meanwhile plugin), and Novell GroupWise as well as tabbed browsing and other goodies. It has some mild issues that are being worked out such as file transfer issues and such, but the updates are frequent and it's a great, fully customizable client that's a great alternative to iChat.
Synergy: An iTunes add-on that's free or $5 if you care to buy a license. This is a great, great program that's entirely customizable and works wonders. You can set up global hot keys to control iTunes regardless of the program you're using if you like, and it's well worth the $5. Additionally, it runs entirely through System Preferences to save real estate and resources. I just checked out M-Beat and they seem to have overlappng functionality, but I can vouch firsthand for Synergy; besides, it's cheaper
Macaroni: This is a regular maintenance program that's free for about 30 days, $9 to buy. It basically keeps your Mac running like it should, including automatically repairing permissions via the Disk Utility tool and other scheduled tasks. Again, runs only in System Preferences and completely customizable.
Diablotin: This program basically helps you manage plug-ins.
Acquistion: A great P2P program that's free or $15 to buy, that's tightly integrated with the Aqua interface. I quite like it when I want to sample a full track of music.
Mac The Ripper: A great tool for backing up DVDs. And yes, I actually use this for legit back ups, as it's a lot easier than lugging a DVD to watch on the laptop.
Also, if it's your first Mac, I highly recommend
Mac OS X: The Missing Manual. It'll help you dig deep into Mac OS X and get familiar with a lot of it; the book is cheap and if you check Fry's ads, they usually have the book for free after a rebate, or other Missing Manual books, which are excellent quick guides into software.
Safari is a good browser and it's what I use most, although I have Opera installed as a back up; I booted IE the second I got it just for good measure. Firefox, by all accounts, is good as well, but I think there's little reason to switch from Safari honestly. Mail is also a very good little program, but I'm not much of e-mail expert; still I have it tied into my Gmail and .Mac accounts and it works fantastic.
Also, Sherlock can be a handy little program for checking movie times and such, although if anyone knows of a weather channel or mini-program that's good and uses minimal resources, I'd like to hear it (let alone any good iCalendars worth subscribing to).
RadTech: This isn't software, but it's a good site full of handy accessories, including a great mouse.
Anyway, welcome to the fold. Bring on Tiger, Apple!
