Welcome to Android! I just got my Hero as well. I've had it for a little over a week and I'm loving it. I have a few apps that work with Stock. Beautiful widgets is one that I love. You have have the HTC clock and weather, but with any skin you want. I also have some fun games: Traffic Jam, Mazeoid II (Which is basically PacMan) and GeoQuiz. I also have a notepad which is great for taking notes. An app which is a must-have is barcode scanner. You can look up apps online and then use the barcode scanner to download them onto your phone. There are also apps that work with barcode scanner while you're in a store. I also have Pandora and Facebook for Android. Both of these are great. Pandora is great because you can listen to any kind of music you want, for free.
I just learned about AppBrain. Basically you can browse the android market from the appbrain website and use the website to install the apps to your phone.
I agree, I had one on mine forever, but haven't used them in a couple months. sometimes i put it in the same pocket as keys and have yet to get a scratch on it. Screen wipes clean with a shirt, too.