I guess many people use their phones differently, so they are in need of different apps.
As for me, I probably use maps, internet, and maybe weather a little. Don't need a lot of crazy apps. Here's my list
1. Dolphin Browser - much better UI than OS version. Pinch + Zoom plus better bookmarks system. Switching between tabs is a breeze.
2. Pandora - Use if often when in the car.
3. Cardiotrainer - Don't use it often, but kinda cool to use it the rare times I work out.
4. Nav Launcher - This makes using google navi 100x better. It's how google navi should've been. This is the missing link.
5. Google voice - Only because there are certain people that I need to give a different # to. It also transcribes your voice messages
As for widgets, I only use two that are a must.
1. Weather forecast - Only app I paid for because I found this to be the best weather widget for my needs.
2. Battery Status Free - Only reason why I choose this one is because if I click on the battery a list of shortcuts for wifi, gps, 3g, screen/sound and battery status comes up. Very useful at times.
Hope your search for the best apps goes well bud. Many many many many many more apps to come soon. So stay tuned
These lists will all change by next year.