Work:
Polaris Office is actually kinda nice. My preferred mobile doc client is Docs to go, but it's not optimized for honeycomb yet (though it does work)
Wyse Pocket Cloud-It's a "log me in" type client so you can access your computers on the go. there are other options for this.
Touchdown is a decent exchange email client for android (and it's tablet optimized). I don't use this since I don't use work email on the go, but the people I know who use it swear by it.
CNN/Pulse/MSNBC RT: News apps. NewsR is a decent Google reader viewer.
Fun:
Plume for Twitter: looks amazing on the transformer screen. I've uninstalled Twitter on my phone (just use Levity for mentions) because using twitter on the bigger screen is so nice.
Gun Bros: It's a free game, and it's addicting. Good way to show off the capabilities of the tablet. THere's a nice selection of HD games, but most of them cost money. They're worth it, but only if you like the genre.
Google Music: If you haven't yet, go to music.google.com and apply for the beta. Having all your music (up to 20k songs) available to you on the go is amazing.
What kind of apps are you looking for specifically? If you're looking for specific apps/types of apps, put them here and I'll try and find android alternative.
Helpful hint: You can go into the settings of the browser and under advanced options set the User Agent to desktop. Most websites won't properly recognize your tablet as a tablet so they will most likely display the mobile (phone) version of the website, which looks horrible on a bigger screen. Dolphin HD browser (free) can be set to identify itself as an iPad, which is helpful since a lot of sites that can't "see" a transformer will see an iPad just fine.
Facebook
Twitter
Instagram