I have a G1 and the apps that I use/would recommend are (all FREE!!):|
ScreenOn - you can set it to keep the screen active when a particular app is in use. Useful if you're using Google Maps for driving directions.
Google Maps - for driving directions it does a good enough job. Make sure you press 'My Location' and the map will track your movements so that your marker is in the middle of the screen.
My Maps Editor - part of the Google Maps family really - useful for saving and sharing map waypoints.
AK Notepad - a simple Notepad style app
ToggleWiFi - gives you a single click button on your main screen to connect to WiFi
Abduction - fun, platform bouncing game. Uses tilt sensor for control. I can't think of a well known equivalent...but I'm sure there is one.
Doom - Probably not worth bothering unless you have a G1 as it uses keyboard keys. Otherwise - it's ace!
Colossal Cave Adventure - classic text adventure
Not as nice as I used to be