I am looking forward to reading all of the brilliant responses!!!

At $15K...
1) Spend a weekend with my ATF at a nice beachside hotel.
2) A nice non-hobby gift for me, and perhaps her. Like new iPads or other tablets, or new phones. Nothing too extravagant.
3) Bank the balance for a hobby fund (there was no stipulation as to how long it took to spend).

Or...if my ATF was not available...
1) Go through my to-do list of a half-dozen or so 'favorites' providers.  
2) A threesome, or two, if any of the providers in the to-do list were truly bi-sexual and bring the other girl.
3) High-End PSE with one, maybe two, of my top favorite half-dozen porn starlets known to provide.
4) Bank the balance for a hobby fund.

I would not travel to a hobby location because I am LE paranoid. Strip clubs are a waste of money, IMO

I would get a nice suite, champagne toast to a great night ahead, foursome, steak or sushi dinner, nightclub or gentlemen's club, back to the room for more fun, sleep all cuddled up with them, legs intertwined, and get woken up in the morning by all three girls playing with the morning wood.

Thinking about doing that for my birthday and I already have an idea of which girls I would choose.

...is out to steal your money from you, especially these guys...

i actually did get a 7K bonus awhile back and spent it on nonstop women.  saw them back to back till by dick got sore and actually hurt to have sex.  then spread them out so had one day rest.  i think i saw about 36 different pussies.  2 repeated due to incredible service.  

looking back i wish i spent some on a pornstar and 3 somes.   total regret  god..what i would give to bang miko lee in the ass!  sigh...i guess next bonus!  miko wait for me baby im cumming!!

First, I'd take 10% and donate it to my favorite, tax-deductible charity. So I feel good that I've done a tiny bit of good in the world.  

Second, I'd take 10% to 20% and put it in my 401K or IRA. If they're already maxed out, I'd put it in an index fund, so I can look at it later and tell myself "well, I didn't blow ALL the money!"

Then, I'd spend the rest on whatever my favorite fantasy scene(s), pornstars, ladies, etc. for as long as I want or until the moolah runs out and I'd be sure to take a few photos or videos so I can relive those times later!

I flew a special friend out for 4 days/3 nights at a 5 star Scottsdale resort earlier this year.  I'd go for the same adventure again, but maybe in someplace like Hawaii (Big Island) for at least a week.

just to get that kind of a bonus. I've never gotten one that high (but then, I've either been self-employed, or worked for some cheap-ass companies....), so I'm not sure what I'd do, though I would certainly set aside some money for fun

I'd see a few on my to do list. A couple caves for over nights. Definitely a threesome.  An I'd like to take a cruise to Mexico with a lady or two. Is there any $$$$$ left?