I use the Melda m spectral dynamics a fair amount.

I'm going to consider both EZD2 and Amplitube instruments. So then, Melodyne followed very closely by Vahalla.

Bat, you can't expect a group of GASaholics to name one plugin. That's like asking a mother of four to name her favorite child.
 
Plus you made it more difficult by saying it could be either your #1 go-to plugin OR just your favorite. Is it a favorite because you use it in every project, because it's easy/fun to use, or maybe it does something unique? Or maybe it's just an old friend you know well.
 
I have more than one that meet all the above criteria. 

I stick IK's Bus Compressor on the final master bus so often I'm actually thinking I should just add it to my main template to save time.  Its "Glue" preset with adjustments for the project work pretty well for me.

bitflipper
Bat, you can't expect a group of GASaholics to name one plugin. That's like asking a mother of four to name her favorite child.
 
Plus you made it more difficult by saying it could be either your #1 go-to plugin OR just your favorite. Is it a favorite because you use it in every project, because it's easy/fun to use, or maybe it does something unique? Or maybe it's just an old friend you know well.
 
I have more than one that meet all the above criteria. 

it's kinda ALL of that, bit!!
LOL
 
me, i'm looking at upgrading soon,
and will hand pick a few 'outside of sonar' plugs to do specific duties..
 
i figure, amongst everyone here who is actively mixing projects,
there is probably one most-used plug that people rely on;
a lot of folks can probably get by with nothing but what comes in the sonar package...
especially the full-blown ones...
 
but the flavors are so varied, among all these different plugs,
and i was looking to get a feel for the most COMMON....
 
i appreciate everyone chiming in with their picks.....

Native Instruments Passive EQ, it sounds good on everything. 

That clarification means a lot actually... If I were going to BUY one, hands down would be Ozone 7 Advanced. As mentioned above is the Swiss Army Knife, and Ozone Advanced negates Alloy 2 since each plug can be used separately on tracks without issue.

no, you are still missing the mark....
 
i want a single instance, of a single plug...
not a suite, not a collection,
even if you can't get it without buying an entire package,
just the one plug.
that means whatever it means... a single module....
a single function.....
a piece of a plug.........!
LOL
 
that's what i'm looking for...
 
 

tomixornot
Nomad Factory - Studio Channel SC 226

 
Interesting.  I have this plug-in, courtesy of buying the total bundle, but I have never once tried using it.  Must check it out!

Maybe I'm missing something here ...it wouldn't be the first time
 
Bat ,
have you switched over yet from XP and SONAR 6 to a more current OS w a more current version of SONAR ?
If you have , do you find it lacking ?
 
Kenny