delorme street atlas 2005-2006 is the best!!! try delorme.com for more info.
Custom, be careful, you're gonna get some folks angry with you. If you don't have a big screen (and I don't meen 7 inches) and preferably a trackball or touchpad, delorme stinks for heavy use. Trust me, I use it every day, and participate in their forums. It's a great program, but the interface just isn't suited to a little carputer screen. Further, it unfortunately is the least suitable package I've found for voice commands (beyond the limited set integrated into it.) I run my system with dragon naturally speaking, but I have to use the keyboard with delorme. On the other hand, delorme has the best voice navigation going. It is the only program I've used that bothers to tell you the name of the street you're turning onto (can be very useful in city driving.) I currently run iGuidance and streets&trips as well. Most days I run iGuidance over delorme, and only rarely use streets & trips (mostly if I have to organise a large number of stops.) If you only want to know how to get from where you are to the next stop, iGuidance is the best (and it's also the best on a small screen.) If you have large numbers of stops you need to organise, streets and trips is the best at juggling stops and re-ordering a complex route. Delorme is the most powerful overall package, has the best trip planning features, best poi searching etc.