Paytunia app for Android is the simplest and fastest (PIN code can be set optionnally)
Too bad it's not on the list.
I assume you are affiliated as simpler and faster than Spinner seams doubtful to me and for my wallet, simple and fast is not the main argument. How about secure and open source?
I use our wallet app easywallet.org - it works as easily as a native app, and recently we introduced one-tap payment -functionality. This is handy in the restaurant I go to, which accepts bitcoins.
Of course this kind of low-security hosted wallet is only suitable for small pocket change. I use it for small payments between friends, and to pay for my lunch in my favourite bitcoin-accepting restaurant, vegemesta

Edit: One-tap-payments:
http://localbitcoins.blogspot.de/2012/09/one-tap-bitcoin-payments-with.htmlAdded, as well as Instawallet. Usability tests still pending.
Easywallet seams to have many more features than instawallet, which I like. Hope I also trust you some day like I trust instawallet (for whatever reason

).
And how about the fees? Also: Would you sell me BTC at 5$?
The Scan QR Code button does
not work on my Motorola Defy but it works on my Motorola XT531. Edit: The defy was just slow. 2 minutes slow. Else the QR-Code integration is cool

The page seams a bit lengthy:
