Actually, I like the LG Optimus interface. The aesthetics of the defaults are a little garish but the functionality is really good. They have the flashiest effects and brightest color backgrounds and most annoying ringtones and notification sounds as defaluts which is what has some folks turned off but once you actually get to the functionality of all the LG specific software it's really useful.
1. Knock, Knock: This has completely changed the way I use devices. Once you find the "sweet spot" for the rhythm and make sure to keep it secure (either firmly in hand or secured on a surface) when you "knock" (but most of the time I actually just lightly press it 2 times in a row) it works very reiably. I think most of the problems people are having is that they don't hold it firm and it doesn't register the "knock" well. Once you get used to it, you want to knock everything you pick up.
2. On Screen Volume Sliders: GREAT option. Whenever there is something you need to turn the volume up or down, you can simply pull the volume down from the notifications and adjust it and you can even individually change the volume on "Media", "Ringtones" and "Notifications". This helps with some of the challenges some folks are having with the buttons being on the back. (I'll talk about buttons in a minute)
3. Settings in notification bar: Really convenient to have all the common settings accessible for toggling on and off in one place without having to take up screen space with widgets. Having it built in and customizible is really convenient.
4. Slide Aside: Really cool feature that lets you hide apps to the left side of the screen that you use all the time. I use it for my media players and email.
5. Camera Custom features: The camera it's self is REALLY good, especially when I use the "Intelligent Auto" feature. The video tracking zoom and tracking audio works really well and is fun to play with.
6. Wireless Storage: Makes transferring files REALLY easy and convenient. It's nice to be able to transfer files without hooking up or installing custom wireless software.
7. Homescreen Rotation: It may seem like a little thing but I like it that the built in Homescreen Launcher rotates orientation and isn't stuck in portrait mode.
8. Homescreen Tilt to move: When moving app shortcuts, widgets, whatever, between homescreens you can tilt the phone left or right and the screens will slide until you get where you want.
9. Bluetooth connection: Connecting and Pairing to devices is VERY fast and connections are really clear.
10. Q-Slide: Never use it. Maybe once they get a few more apps for it, I'll be tempted to use it but I really don't use it right now.
11. Keyboard: Really versatile with either a peck or swipe feature that both work really well. Also, having the numbers always present is really handy! and being able to shrink it for onehanded use or split it for landscape use is really nice too.
Buttons on the Back: This isn't software related but it is specific to the G2. On the Verizon version, I found they were REALLY easy to use once I had it in a case. Before, it was a little hard to find the buttons but with them being dropped below the surface of the case, my hand falls to them easily and they are easier to discern the difference between them after a few days.
I'm sure there are other things I've left off but those are the items right off the top of my head. Honestly, everything is so well executed I really like it. I'm normally one who changes out for other launchers but this one is really well put together and some of the features have become so 2nd nature now I don't want to do without them. I really am thrilled with it.