As someone who once made a living as a graphic artist, my favorite is the original one. But the main problem with all of them is the shape. If this logo is going to be used on a website, choose a shape that is plenty different from a banner.
mikemicki's designs are nice for banners but not for a logo. Especially the animated one. How are you going to use an animated logo outside the web?
A logo is part of your "company's" image so it is very important. And it needs to work wherever you are going to use it such as on letterhead, invoices, business cards, etc. Even if today you are only using it on a website, it still needs to be usable somewhere else. You just never know what the future will bring.
When I designed a logo with more than one color I also made sure it worked with a one color version. And if it didn't look good in B&W, I'd go back to the drawing board. Again, one never knows.
It also helps to understand the printing industry when you create designs such as a logo. Even in the age of digital printing some of the old rules still apply.
I am in the process of designing a t-shirt for a non-profit group I belong to and because we want as many members as possible to buy it, so that people know who we are when we do an event, it has to be kept cheap. At the same time, we want it to look good enough that we may be able to sell it to raise some money. So far, the old screenprinting technique is still the best looking one and, to keep it cheap, it is going to be two colors only and it needs to look good on either a white or color t-shirt. Those two colors will not touch because, if they did, it would be more expensive to print...
Sorry for the lesson in printing but, with the age of computers, I have seen many people call themselves designers whose designs are unprintable at a reasonable cost.
