Adobe Reader If you've never had to read a PDF, you're probably living under a rock somewhere and not even on this website. So I will assume that you have. Every phone and tablet needs this simple app because sooner or later, you WILL need it.
Adobe AIR You will probably never open this app, but you'll need it. Adobe AIR allows you to run web-based apps (Twidroyd comes to mind) and is a foundation for many app developers. Apps that require AIR will prompt you to download it. Just get it now anyway.
Adobe Photoshop Express The bare-bones of the backbone of photo editing... this capable app is great for photographers on the go.
Adobe Flash Player 11 Remember that rock those non-PDF people were living under? You're under only a slightly smaller one if you haven't heard of Adobe Flash on the ongoing Apple-Android debate. Apple doesn't. Android DOES. This app gives you full-featured flash content in your browser.
CamScanner -Phone PDF Creator It's not an official Adobe app, but this handy one uses your phone's camera to scan documents and create PDFs. Handy-dandy for emailing, and better quality than a photo in some cases.
Adobe AIR 1.5 Cookbook LEARN. Love apps? The O'Reilly series of books is seminal in the software world, and this ebook (read it on Aldiko) will get you started as a developer.