I've always liked most of the text-only logotypes. Jupiter, one of the game companies that worked on The World Ends With You:
(pixelated a bit but that's the best pic I found)
You know a logo is efficient when they don't need to change it for people to recognize. Also when it always looks good no matter what decade it "lives" in.
When I look at Namco, I always have the logo from the Canadian National in mind. They never changed their logo and it's been nearly 100 years, yet it still looks great. Might be the color and the font...
I do like Hal Lab, and Hudson Soft too.