If budget is not a constraint then you should go for the 18-135mm... It allows more creativity on your photography.
My first lens is 18-55mm which I regretted buying then as I felt that it limits my creativity. However, after using the camera for a while, I realised that most of my shots (90%) falls within the range of 18-35mm cos I mainly used them to shoot my family and friends at home. So my 18-55mm isn't really that bad after all. The only time that I regretted not having a 18-135mm is , when I wanted more zoom at a event or outdoor where I wanted to capture "moments" of pple without alerting them.
However, after reading up more. I found more that longer zoom isn't necessary that perfect after all. Cos although they provide you the zoom, the image qualities it produces is not as good as those prime or shorter zoom lens. Furthermore, the aperture on this long zoom lens are quite small (i.e slower lens). So your image will suffer more blur when taking a moving object. Now even when the subject is a static one, you might encounter blur image also if you zoom it to the max telephoto range cos at this range, it requires you to stabilise the camera more (e.g on tripod or holding it really firm and steady).
Another disadvantage which I personally feel about longer zoom lens is that sometime by the time you zoom till the 135mm or 200mm, the "moment" is already gone (unless you leave it at that range through out).
Lastly, about this longer zoom lens is that as their aperture are usually small (F3.5 at 18mm, F5.6 at 135mm) so you cant really achieve as much bokeh as compared to a prime fast lens or F2.8 zoom lens. This again is the limitation of longer zoom lens.
So do take notes of the limitation of these lens before deciding which one to buy. And take future lens upgrade into consideration too. Despite all that I have mentioned about the longer zoom lens, I will still desire to have one if money is not a problem (18-135mm should serves you better than 18-55mm if you are not very particular about image qualities). Of cos topping it up with many other fast prime and fast shorter zoom lens...
Hope this helps...