Portal was great. I remember they switched around through Everquest, the Sims, Second Life, Star Wars Galaxies. There was a lot of great classic games they used to convey the show. I remember the Drifter in the show being voiced by the same dude who voices the Colonel in Metal Gear Solid. It was a good time.
I think G4's biggest problem was like as I stated before the concept was EXTREMELY ahead of it's time. It came out at the best time when internet was still not the best it can be but it allowed people to watch it to get actual gameplay for games instead of just reading them in like tips and tricks. Seeing video gameplay of all these different games especially through Cinematech, Blister(The action game show), and even Cheat! (With that fucking nerd Cory Rouse), was enough to get you interested in games since you were seeing them play out in front of you.
You look at a show like G4TV.com, that basically plays out as a podcast. They have a recorded conversation with a caller, they sometimes have guests like Tommy Tallarico, the hosts were great (Laura Foy was fucking hot), and the conversations they had were genuine. Now we have all these different podcasts and the closest I feel to capture that atmosphere is Giant Bomb, since they can just meme on each other.
Also I'm shocked you guys haven't brought up Judgement Day. Victor Lucas is such a cuck when talking about certain games, but Tommy Tallarico just fucking tells it as it is. I love that dude, and his infamous High Heat Major League Baseball 2003 review