I've been a photographer for ~25years. Here are my thoughts, hope they help.
I feel your question is to vague to give any definitive recommendation.
What type of photography do you do most? Landscapes, Portraits, Wildlife, Birding, Macro or just general snapshots.
What is it about your current lenses that you are unhappy with? Focal length, max aperture, bokeh, vignetting, AF speed, sharpness, distortion, colors, build quality, etc...
You also have to be willing to critique yourself. When you look at a shot you're unhappy with, is it really your gear to blame, or something you did wrong? eg. 'Is the sharpness of that lens really that bad, or did I introduce motion blur with poor technique?'
If you don't know enough to answer those questions, then I'd stick with the kit lenses for a while until your skills increase. For most beginners it is their own skills that hold them back and not any gear. Eventually as your skills grow you will reach a point where you realize. "I don't like this lens because of 'X'. " or "I want a lens with better 'Y' " or "I'm missing shots because of 'Z'. "
At that point you can go someplace like
www.slrgear.com www.dxomark.com or
www.dpreview.com and read a bunch of specs and reviews to see what suits your needs and budget. Just remember top quality optics are NOT cheap, expect to pay at least 3x-4x the money for a decent step up from the kit lenses, and the top of the line glass will be 3x more again.