I would love some help & any advice please on what lens to choose. I have a canon 500D with the twin lens kit.

I was beginning to lean towards bird photography however due to a few problems that may have to wait for a while.

What I really would like is a nice little lens that will take nice sharp pics. I did read on here recently that someone else was after similar but i cannot find the thread. I would like to be able to use it for some portraits & general purpose. I would like to say I want to specialize in just one type of photography but for now I will have to lean towards some nice landscapes & portraits. I have a new Grandson & thought maybe this was the right time to really try & get serious but I am unsure about what lens? My budget is not an open cheque book....Oh how I wish.

Thank you so much for your time.