SwitchPro Widget
Your typical switches for GPS, WiFi, auto-screen rotation, etc... What's nice about this widget is that it lets you select not only how wide your widget should be (from 1 to 4 columns), but also lets you choose up to two widgets per column. So, for example, you could have a widget that spans 4 columns with 7 buttons in it and it will automatically center it for you. If you don't like that, you can delete that widget and make a new one--if you change your mind, you can easily switch back to the first (or any other) setup that you've made because it automatically saves each widget setup that you create. Dig it.
Astrid Tasks
Great to-do list widget. You can choose from 4 priority levels, and it syncs up with Google Tasks and Producteev, if you use either of those. If you don't... You can still sync it up to them, just in case you decide you'd like to someday--then you've already got your to-do lists set up!
Mint.com*
If you're fiscally irresponsible like me, you need this app (and an account on mint.com). Mint keeps track of all your balances in each and every bank account or credit card that you have. You can choose which accounts or cards are shown in your grand total of "available funds," which is great. This is actually probably my favourite widget that I currently use.
AudioManager
Gives a super awesome display for all of your volumes on your phone (alarm, media, alerts, ringer, system, call voice). Tapping the widget brings up an awesome UI with 6 sliders (and two checkboxes for vibration) for changing the volume levels. A cool feature that is included here is that you can set different volume levels for different modes on your phone and cycle through them. For example, there is a normal, vibrate, and silent mode that all have individual sound settings. I then use SwitchPro Widget's button to cycle through each sound mode.
