I've watched this thread and am very surprised no one has mentioned  Arturia Moog Modular V. To me this is the one to get for a really great sounding Moog VI.
 

Weren't there a couple of Moog packs in one of our monthly freebies a little while ago??

I DO love the Modular V - it's my favorite Moog-like synth.
 
I didn't mention it, because I took the original poster's question to be about getting Moog-like sounds from things within X3.  I mentioned some free ones, thinking that was what he was looking for.
 
Bob Bone
 
 
 

Bob to me when anyone talks Moog they need to talk MMV. SOS did a review of it years ago and man they said it was very close to the real thing. Moog himself endorsed it. 
 
Its only problem is it is too faithful to a Moog modular. Its a beast to program. The good news is you can save the patch. 

robert_e_bone
I DO love the Modular V - it's my favorite Moog-like synth.
 
I didn't mention it, because I took the original poster's question to be about getting Moog-like sounds from things within X3.  I mentioned some free ones, thinking that was what he was looking for.
 
Bob Bone
 
 
 

Zaxtly, that's why I mentioned Pentagon. I think the OP was using "Moog" to refer to analogue synths in general as he mentions Tony Banks who used ARP in the early days.
My "Moog" goto has always been GForce Minimonsta which features as the lead synth on the track in my signature. I recently bought the Artura V collection and I am getting into the Modular V. As John said its a beast to program.

Yup - here is their review of it:
 
http://www.soundonsound.com/sos/jul03/articles/arturiamoog.asp
 
There are some synth bass sounds that are absolutely the best I have ever heard from any synth, hardware or software.
 
Bob Bone
 

Minimonsta is great!

Yeah - I was leaning toward picking that one up, but then I happened across the Arutia V Collection sale - they had it at 50% off, for a little while at the beginning of the year.
 
I picked it up for $199, and for 9 synths and 30 drum machines, I couldn't pass that up.
 
Bob Bone
 

True that is hard to resist. On the whole I like the GMedia ones a little better (Oddity is also great and so is MTron Pro of course) but for that price I would probably have jumped on the Arturia collection too :)

I was lucky enough to score the free Minimoog V original a year or so ago when Arturia were giving it away free on World Music Day.
 
I must say it is also an amazing sounding analog synth and very much like the original as well. Great thing about this is that it has a polyphonic switch and when you flip it you get a monster polyphonic version of a Mini Moog!
Highly recommended too. It is quite affordable as well.
 
I once had a room full of analog synths including a Korg modular setup and I have got rid of them all now and dont miss them one bit. I still have all the sounds available without the problems!
 
Another really couple of great freebies too is the old Synth1 that has been around for years and it still sounds excellent (there are tons of free patches on line for Synth1 as well) and also a very nice freebie called Superwave P8. It looks a bit like a Roland synth and sounds it too.
 
http://www.superwavesynths.co.uk/product_p8.htm
 
http://www.kvraudio.com/product/synth1-by-ichiro-toda
 
These are two of the best free analog synths you will find.
 
John that Arturia Moog Modular must be a beast. I had a rather large Korg Modular too and I know how incredible they can be. Great that you can store a patch!!! Sometimes I would spend many hours getting a sound from my Korg modular but it may have been very late and I was too tired to lay down the track (onto tape of course) so I would not touch a thing and turn it off. Next morning after getting up and even letting it warm up for a while that sound never came back quite the same! You had to track the part at the time or risk never hearing it the same way again!