1) ASTRO File Manager This app might just be essential. It's a full-featured file manager that lets you view and manage the files on your Droid without having to plug it into your computer. You can even use it to backup your Android apps to your SD card. Free and paid. The free version features ads. The paid version goes for $2.99 and removes the ads.
2) TouchDown for Tablets Optimized specifically for Android tablets, this productivity software taps into your corporate Exchange server to give you your e-mail, contacts, calendar and tasks all in a single tabbed view. Free.
3) Catch Notes This app, formerly known as 3banana Notes, lets you capture thoughts and ideas in text, voice, images and locations. You can then synch and back it up for free to Catch.com. You can passcode protect your activity stream, set reminders, share content and even organize it with hashtags. Free.
4) Skifta This app turns your Android device into a global remote control. Certified by the Digital Network Living Alliance (DNLA), Skifta allows your Android device to stream onboard media to any DNLA-enabled device, include TVs, stereos, PCs and the Sony PlayStation 3. Free.
5) Amazon Kindle for Android Want to read an electronic book, newspaper or magazine but don't have your Kindle with you? Or don't have a Kindle at all? It's not a problem with this app, which allows you to read any of 900,000 Kindle-formatted books with your Android device. And Amazon's Whispersync that your last page read, bookmarks, notes and highlights will sync across your various devices. Free.
6) Easytether Pro Looking for a solution to turn your Android phone into a mobile modem? Easytether Pro lets you tether your phone to Windows, Mac OS X, Ubuntu Linux, PS3, Wii and Xbox 360 devices with no tether fees and without requiring root. An easy-to-use wizard guides you through the tethering process. Paid: $9.99.
7) Kongregate Arcade for Android Want to stay up on the newest and hottest Flash games around? This app gives you free access to more than 300 games from the Kongregate community and fully integrates with your existing Kongregate Web account. Free.
8) Beautiful Widgets Not content with the widgets, themes and skins that came with your Android device? This app is what you need. It features hundreds of downloadable skins. Paid: $2.82.
9) WolframAlpha Access WolframAlpha's computational knowledge engine from your phone with this app. Also available for free via the WolframAlpha Web site, the app calculates the answers to complex mathematic and scientific problems in an instant. The app version adds a keyboard with all manner of mathematic and scientific symbols to make entering queries a snap. Paid: $1.99.
10) Anti-Virus Pro Concerned about malware, viruses and SMS spam? Anti-Virus Pro is a comprehensive security suite for Android that can scan apps, files, settings and media in real time. Paid: $9.99.
11) Google Body This app from Google allows you to search and navigate an interactive 3D model of the human body. It gives you the ability to view different anatomical layers, zoom in and navigate straight to parts that interest you. Free.
12) Dropbox This client for the Dropbox cloud-sharing file storage service makes it easy to get files onto your phone without explicit synching. You can shovel files into it from any of your computers and then access them from any other computer or phone. Free.
13) Layar Turn your phone into an Augmented Reality device with Layar. It uses your phone's camera, compass and GPS data to identify your location and field of view, retrieves data based on those geographical coordinates and then layers that data over the camera view. Free.
14) ESPN ScoreCenter Get comprehensive ESPN sports coverage on your Android phone with this app. It provides near-real-time scores and schedules. Free.
15) Yelp Yelp for Android determines your current location and then lets you search for nearby businesses, read reviews and so on. It also lets users filter by "Price," "Open Now," "Special Offers" and "Hot on Yelp." Free.
16) Lookout Want to protect your phone? Lookout does just about everything. It provides security against mobile viruses, malware and hackers, backs up your data and even locates your lost or stolen device on a map from the Web. And if you can't find it, you can use Lookout to make your phone "scream" or simply wipe out all the data on it. Free.
17) Nimbuzz This communication app allows you to connect to all your online friends, whether they use Skype, Facebook, Windows Live Messenger, Yahoo!, GoogleTalk, AIM, ICQ, MySpace, or StudiVZ Hyves. Free.