When you see all these logos in a list, none of them particularly shout the web at me. I'm not smitten by any. The only standout one was the little spaceman with the earth in his visor's reflection. All a bit drab save for Iceweasel. I think I prefered the netscape logo.
I assume you mean Epiphany's logo of an earth with a pointer on top. Is an image of the earth synonymous with viewing web pages? Not really, but an image of the earth has global connotations. Nightly's logo looks like an earth from space (at night), with little dots between cities/nodes I guess representing both lights and communications. It's not that obvious and doesn't translate well. The pointer on the Epiphany logo feels a little dated.
At least the Navigator wheel conjures up the idea that I'm out at sea at the helm. A little romantic I know. I quite like the image on William Gibson's book virtual light, the idea of virtual glasses.