Thanks for the fantastic responses so far! My budget is up to ~ $4400 US. A lot of money, but then again I don't do this every year, even every several years. Based on how good the images from the 50 1.4 have been, "you get what you pay for".
Then again, if I become infected with NAS, I hear there is no cure....
Everyone has given good advice, but keep in mind that it is largely biased to their vision of what they enjoy shooting, and what they think covers day-to-day photography - again from their point of view.
Mine would be the same. I've gravitated to shooting portraits and would suggest longish, fast lenses, perhaps one of them a macro.
One thing I would recommend for you to do is look at a lot of pictures and see what you really like and would like to try to mimic in your personal work and see what focal length (and f-stop, shutter speed, etc.) was used to make the photograph. That would help you in developing your vision, too (while it might seem like copying - painters learn by copying masters ;-) ).