Man.. you are lucky! Congratulations!
Hmm.. i would buy
- a rompler (motif, fantom)
- a sampler (mv 8800, mpc 2500/4000)
- a analog synth (dave smith, moog)
- a control surface (mackie mcu pro, m-audio projectmix)
- some good preamp and outboard fx / filters
- very good headphones (akg, etc.. studio line)
But that's just me.. i am a composer.
What music do you want to make?
Given that you don't own any of those yet you are free to trial anything until you've found your weapon of choice. My top priority would be to find my centerpiece first.. then look for gear that compliments.
I would just spent the money on stuff that appeal to me and care later about the details. You can return the items within 30 days on most retailers (money back garranty). So just cop them, try them and then decide.
My shops here even suggest me to do so and offer that they will take it back, no matter what, if i am not happy with it.
have fun!