There are lot's of great ROM's out there, aospCM7 is my fav, but keep in mind there are others that people love and swear by.
Here's a quick walk through the CyanogenMod settings you get, some are available on other ROMs or via apps, but these are all included in aospCM7:
Applications
>Move applications to sdcard (native support, no need for scripts or apps)
>Default selection for install location (internal or sdcard)
>Permission Management (allow or revoke individual permissions on any app)
>Phone Goggles (filter outgoing communications)
Display
>Rotate 180 Degrees (auto rotate will go upside down when you turn your phone that way)
>Screen On Animation (looks like an old fashioned tube TV turning on)
>Screen Off Animation (looks like an old fashioned tube TV turning off)
Input
>Long Press Home Key (set it to an app, or a direct method of an app, or to show last used apps)
>Search Key Behavior (assign any function/app to search key and to long pressing search key)
>Haptic Feedback Tweaks (adjust vibrations however you like)
>Volume Rocker Wake (pressing up/down volume wakes the screen)
>Volume Button Music Control (seek music tracks by long pressing volume buttons)
Interface
>Power Prompt (turn on/off the prompt when you power off)
>Notification Power Widget (adds a widget to the notification dropdown with controls for tons of features like wifi on/off, screen brightness, data/3g on/off, gps on/off, etc)
>Staus Bar Tweaks
>>Show Clock (turn on/off the status bar clock)
>>AmPm Style (large/small ampm indicator)
>>Battery Percentage (show battery percentage)
>>Compact Carrier Label (puts the carrier name in the notification title block, saving space)
>>Status Bar Brightness Control (allows you to change your brightness level by swiping the status bar)
>Render Effect (changes the rendering colors for better viewing under certain light conditions)
>Reflow after Pinch in Browser (immediately reflows text after zooming in/out)
>Overscroll Effect (the edge of moveable objects/menus can glow, bounce, or both)
>Overscrolling Weight (the amount of bouncing when overscrolling)
Lockscreen Settings
>Style Options
>>Lockscreen Style (sliding tab, rotary, rotary revamped, or lense)
>>Incoming Call Style (sliding tab, rotary, or rotary revamped call answer slider)
>>Custom App Starter (add a second slider on the lockscreen to access an app directly)
>>Drag Down to Unlock (drag the rotary wheel down to unlock, drag right to launch an app)
>>Hide Rotary Arrows (hides the hint as to which way to rotate)
>>Message Icon for Custom App (if using second slider, select messaging icon for it)
>>Custom Application (custom app to launch from second slider)
>Widget Options
>>Always Display Battery Percentage (displays batter percentage on the lockscreen)
>>Lockscreen Music Controls (show music player controls on lockscreen)
>>Display Song Name
>>Display Album Art
>>Display music controls when a headset is being used
>>Always Display Music Controls
>Unlock Options
>>Menu Unlock (press menu key to unlock screen)
>>Quick Unlock (if you use a pin, will activate as soon as pin is entered, no button to press)
>>Disable Unlock Slider (for use with gestures on the lockscreen)
>Lockscreen Gestures
>>Use Lockscren Gestures (enables gestures on the lockscreen for unlocking and app launching)
>>Show Gesture Trails (show a trail of your finger movement on the lockscreen)
>>Sensitivity (how sensitive to the proper gesture should the phone be, or how strict)
>>Gesture Color (if showing gesture trail, choose it's color)
>>Build Gestures (set gestures to unlock, launch any app, and many direct app methods)
>Delay and Timeout
>>Set Screen Timeout Delay
>>Set Screen Turnoff Delay
Performance
>CPU Settings
>>Available Governors (conservative, on demand, or interactive cpu governors)
>>Min CPU Frequency (set as low as 122mhz, I don't recommend lower than 320, I use 480)
>>Max CPU Frequency (set as high as 864, most Optimus Vs are stable 787-825, ymmv)
>>Set on Boot (you don't want to set a high max on boot when testing your phones limits)
>Use JIT (JIT is Just In Time compilation, a faster more efficient way to execute code)
>Enable Surface Dithering (improves image quality, at a slight decrease in performance)
>Allow Purging of Assets (free up ram memory when possible from bitmap assets)
>Lock Home In Memory (tries to keep the home app in memory at all times)
>Lock Messaging App in Memory (avoid lost messages when memory is low)
>VM Heap Size (adjust the vm heap, allows for faster code execution)
Sound
>Notification Focus (other sounds lower their volume when notification sounds play)
>Silent State (adds a state for complete silence to volume controls)
>Vibrate During Calls (notifications will vibrate during calls)
>Quiet Hours (sub menu for adjusting all sounds/vibrations during defined quiet hours)
>Headset Submenus (change where/when/how notifcations/alarms/ringtones play when using headset)
Tablet Tweaks
>Bottom Status Bar (moves the status bar to the bottom of the screen)
>Dead Zone (if bottom status bar is enabled, create a dead zone in the middle of it)
>Disable Lockscreen (never show the lockscreen, not on wake or on booting/rebooting)
Outside the CyanogenMod settings, aospCM7 also has native 2sd support, native wifi tethering, extra developers tools, no VM bloatware.
As far as ROMs for the Optimus V go, aospCM7 is also the only ROM that plays Netflix without a green bar across the top of the video. It is also the only ROM that is Android 2.3.4, allowing the use of more built in Android features and expandables such as Arduino. And it is the only ROM that allows you to revoke or allow indivudal permissions on any app, really awesome feature from the Cyanogen team.
Main Cons:
Limited interaction with the developer. He does this for his own phone, and shares with the rest of us.
Trouble keeping Bluetooth devices paired
Headsets aren't fully functional (some have more luck than others)
Camera app doesn't autofocus (there is a flashable fix, real easy) and zoom doesn't work properly
