Hi Susie,
Simple is always better when doing a logo design, so I would definitely go for #3 in your current selection.
At the risk of being pedantic, here are the characteristics of a good logo:
It should be simple. Look at the logos of all leading brands in the world, and you'll see they all have this in common. In most cases, people will only get a glimpse of your logo, and simple images are easier to take in and remember. following on from this...
It should be memorable. Your logo is the icon of your business, so you want people to remember it. Therefore, your logo should be appropriate in style to your business, and the design should be eyecatching. More on this later.
It should work well in any size. Think about the possible applications on the logo... website, letterheads, business cards, signage, vehicle applications, and so on. It should be easily and consistently applied across all of them. For this reason, the logo has to be in vector format, so you can scale it up and down as much as you like without losing quality, and again, it should be simple and appropriate enough to work on any layout.
It should look as good in black and white was it does in colour. This isn't just for the aging fax machine... it's an acid test for good design. If it doesn't look good in black and white, chances are you're using too many colours or shades and your logo is too complex.
Have a look at
Logo Of The Day to get some great logo design inspiration.