So I'm a software guy all around... I've never been interested in playing with hardware synthesizers... I respect them, I think they look cool, I love the music that's been made with them... But for me, I've never known what I would do with one that I can't do with software (with a big stressing on the word "I" because I know other people could get all kinds of crazy stuff out of them, but I don't know about me specifically).
 
So with that said, if I wanted to spend a little money and add ONE to my studio to sit next to my MIDI controller that I normally use with 100% software... What would be one that would be not crazy expensive, but special and something that's going to be well... DIFFERENT from what I can already do with all the software I have?
 
Just something I've been thinking about...

Budget?

Honestly at this point it's just thinking out loud but lets say staying under $1000 for sure... Preferably lower than that.

I have got a few hardware synths actually and yes there are some that no software can emulate well. One is the Kawai K5000W and the other a Roland JD800.
 
But for me right now the ultimate machine is the new Dave Smith OB6 which is a combination Oberheim and Prophet instrument.  OMG!  Out of your price range though but maybe keep an open mind about the new Behringer Deep Mind 12.  I think you will find it will be well priced and sound pretty decent too.
 
One thing to keep in mind.  If you are going to invest make sure it has a lot of control over its parameters. eg many sliders and knobs such as the Roland JD800. The Kawai is not good in this area, it just has a sound like no other.  Being able to make sounds from scratch or edit them on the fly while playing is really something else.
 
Another idea is a second hand Supernova II. Although it is a modeling device it sounds amazing and very nice to use.

If I had the money I'd buy a Roland
http://www.musiciansfriend.com/synthesizers/roland-vr-09-v-combo-organ?src=3soswxxa
 
Second hand I'd go looking for the VK-7 .
I use a lot of Hammond sounds on my tracks so it would be cool to have one just to inspire..
I already have an old Korg Poly 8000 which is fun to mess around with if I need a big fat synth sound. Got it for $50. It makes a cool controller but it takes up too much room on my desk.

I have a Roland Juno 106 that my keyboard player gave me back in the 80's. The last time I fired it up was in 2000. It worked fine as far as I can tell because I don't know how to use it. Lol. I never learned how to use it. I don't like musical instruments going to waste sitting in a closet.
 
I found a Youtube video of a guy demonstrating it.
 
https://www.youtube.com/watch?v=W0xOcfzrMG0

I would suggest a used Moog Phatty.  
 
#1 reason - it's a Moog
 
#2 it is simple and fun to play and sounds fantastic
 
and it isn't so shabby of a midi controller itself

I've had a few people suggest that Behringer DeepMind 12 and it definitely looks awesome. I have plenty of reading up and Youtube videos to watch on all these different models, but thanks for all the suggestions. Definitely helps with narrowing down a little bit :-)

I think you have to be looking at the opposite end of the scale, go analogue and see if the grass is greener.

I've been thinking about getting a monophonic bass synth myself...not sure which to go for.

anything with 42 in the name ;-)