OK, which ROM is the best? It depends on what are you looking for.
I look for functionality, the more the merrier/stability/wifi hotspot/esthetic (themes?)/recent update or activities
I have tried the following, each one of the them is enough to shame the stock ROM from Optimus in miles. In general, they ALL are fairly stable, no random crash or FC, runs pretty slick and peppy, battery last at least a day on fair use, WIFI stays on without dropping, GooglePlay works, boot relatively fast. I jotted these down from memory lane
. Again, they ALL are so good, that, in practical there is no reason to flash the other, except I am looking for wifi hotspot because of the Nexus7.
Backside IHO w the greenmachine theme: JerryScript, CM7.1, initial 7/20/2011, latest 05022012; very slick/stable/fast, everything works, including WIFIhotspot;
SIII for Optimus V: ilikechicken123, his 1st port, CM7.2, initial 09062012, latest 091912; stable/fast/esthetic to the eyes, this is the newest among the four, everything except wifihotspot works and works very fast.
Ginger Snapp, finale, ThatGuyLurkin, our 14 year old young blood, CM7.2, initial 07/16/2012, latest ver 2.2; everything works including wifihotspot; Fast, pretty, slick, there is no reason to leave Ginger Snapp other than being curious about ICS.
Paranoid Android, ThatGuyLurkin, CM9 and ICS port, initial 06262012, latest 08152012, probably the most stable ICS port so far, admittedly I have only tried one, everything works except wifihotspot, fast/pretty and surprisingly stable, zero clash or FC except when attempted to do wifihotspot.
Again, I repeat, any one of them is enough to serve your needs, I tried them mainly because of curiosity AND looking for wifihotspot. I am confident you will like any one of the above. I pick these ROMs by random. I am sure the other listed under OP is equally fantastic.
Hope this helps,
bun