Need Lens Suggestion Please

Firstly, stick with Canon lens as they can all be calibrated with your body should it ever be needed. The EFS 17-85IS is a good all rounder with a stabiliser. For a little bit more cash you could get an EFS 18-200 also with a stabiliser and much more zoom.

This is a very subjective issue, what is right for one person is not always right for another... however, from my own experience I would reccomend 2 lenses -
1. The EF-S 17-55mm F2.8 IS. I own this, it is a fantastic lens, never let me down and is on my camera 99% of the time. I prefer it over my 70-200mm F4L unless I really need the longer zoom. It is not a cheap lens however. Wide angle makes it great for landscapes and the fast lens makes it good for portraits too, but you may have to get a bit closer to your subject. If you like the focal range of the kit lens, but wish it was better, this is the lens for you. It is a 77mm thread on the end, so the lens barrel gets in the way of the inbuilt flash causing shadow on the bottom of all your pictures - you NEED to get an external flash unit with this lens. I got a 430EX and am extremely happy with the combination.
2. The EF 24-105mm F4L. Often stated as a great all-rounder, it was a tough call between this and the other lens for me, but the wider angle, larger aperture and IS made my mind up. If you need a bit more reach, or think your F1.8 and kit lenses don't go far enough, forcing you to use the 70-200mm often, you may like to consider this lens.

I use my 17-55mm for most work and it comes into its own for indoor/evening parties. Never miss a shot using Tv mode and a shutter speed of around 60ms with the 430EX flash.
I only ever use the 70-200mm for daytime outdoor work, such as school sportsdays or photographing animals down on the farm etc.

Trust this solves your question!