No particular order except first one:
1. Astro file manager. This should be part of Android's OS
2. Shazaam. Great music ID and tag app
3. Tunewuki. Another great music app
4. Shopsavvy. Makes your phone a valuable shopping tool- Barcode scanner and price comparisons!
5. eBay. Much better than using the eBay homepage
6. Jetflicks. True HQ video that has a TON of TV series including the entire Seinfeld collection. Worth the investment.
7. Car mode. Handy app that you can put on your main page for speaker calls.
8. PicSay. Great image app with edit and art functions.
9. Jewellust. Most addicting game ever.
10. All the game emulators: Gameboid, Genoid, Nesoid, Snesoid, Segoid, Jarcade, Android Arcade.
In regards to item 10. , you will have thousands of game options and the console emulators on Android play better and are more compatible with games than any other phone OS. This is based on a G1 at 528mhz, so Droid should be better
I say "basic" in the title, since all Droids should have em' Maximum fun power!