Some of my favorite that work well:
OI Notepad...allows importing of Outlook/Palm notes/memos via CSV file (export)
Ring Toggle (switch between vib/ring, ring, vibe, silent in two clicks)
Beautiful Widgets (bunch of widgets for home screen, including cool time/weather widget)
Laik Agenda widget - your day's calendar on your home screen, very nice
TuneWiki (play your music w/timed lyrics, see videos from Youtube from the songs you play)
Flickster (search movies, theaters, showtimes, see trailers, buy tickets, etc.)
MountUSB (one-click mount/unmount via USB)
BeyoundPod (podcast downloader/streamer)
Bubble (use phone as a level)
Compass (use phone as a compass)
CardioTrainer (plan/track workouts)
KeepScreen (keep screen from timing out on selected applications)
Barcode Scanner (scan product barcodes to see pricing/availability, and
Android App barcodes to install from Marketplace)
WallSwitch (automatic timed switching between your wallpaper collection)
Unit Converter (convert just about any unit from one measure to another)
Stopwatch (stop watch)
Scan to PDF (use camera to create PDFs)
Draw! (Draw on screen w/your finger)
Google Listen (Search for and download or stream media, like podcasts, etc.)
Album Art Grabber (Gets any missing album art for your Droid...you may have to restart the Droid for the album art to appear after it has been grabbed)
Missed Reminder (Repeating reminders for missed calls and SMS/MMS)
Pure Calendar Widget (
Pure Calendar widget (agenda) v1.5.1 Application for Android | Productivity) Agenda view on home page