But I'm still not clear why you want these plug-ins, or where you feel your existing setup is deficient. It's much easier to make recommendations if you can specify your needs.
QuoteReply

I suppose I am asking the question from the other point of view...

I am in a fortunate position where I can buy some plugins at the moment and Waves, Ozone etc. are names that keep cropping up in videos I am watching

I am just starting to research what is "out there" and wondered what other people are using

If everyone says - "xyz is a must have and I use it on all my projects because..." I can check it out

Alternatively, if the feeling is Sonar has everything and nothing else is worth looking at then that is great

There are no specific needs I have identified yet - but then again I didn't know I needed things like "speed comping" or the "Pro Channel" before I looked at X3 - so I wondered what others felt they needed above and beyond what X3 producer offers

I use Waves more for channel related stuff and effects and I use Ozone for demo level mastering. Ozone is nice because you can grab a preset that's in the ballpark, tweak it and get what you want without a lot of fiddling. If you're doing a final mix on a 6 month recording project, you'll probably want to send your mix out to get mastered by someone who knows what they're doing. On the other hand if you're just shopping your song ideas around, Ozone can make them sound pretty good.
I'd go for Ozone and pick up a few Waves channel strips with whatever is left over.

If you don't know what you're missing, you don't need anything else.  However, get something like your Waves or Ozone, you suggested, and learn whether you spent your money wisely or not.  Might as well invest in some learning experience down that path.
 
And...I think indirectly, the point is you don't need anything, because it's like saying getting another guitar will help my playing....when you already have 10 guitars.

Honestly, I'd look at stuff that is in front of your computer...like mics, pres, better sound sources and techniques.  That is much more suited it sounds like, to "go to the next level" in my opinion.  Then think about better monitors, acoustic surroundings...  you get the picture.  Your software probably already exceeds what you've got in these areas.
I say that, because I listen to people's recordings and they have a huge list of software, etc...  and their recordings still sound amateurish in many regards.  It's clean because of the format, but they haven't mastered so many other areas involved with "getting to the next level".
 
But shopping is always fun for audio stuff!!

Shopping? Did someone mention shopping?

Yeah, forget everything I said, I love shopping



Seriously though, I like the interfaces in the FabFilter plugs and I like the sounds I can get out of them. But I only get those sounds because I've invested time learning to use them through experimentation.

I could just have easily chosen a similar suite of plugs from a different software house and with a similar investment in learning time I'm sure I would love them just as much.
This is why it's so difficult to recommend one set of plugs over another, because so much ultimately depends on the person using them.

The plugs supplied with Sonar Pro are very capable, the addition of the extra PC modules makes the stock set very hard to beat.

If you own Producer I don't think a "Suite" is the way to go because it already has so much. I'd upgrade the things you like (I'd personally recommend the TH2 upgrade but I'm a guitar hound) that are included then focus on getting a mastering suite to compliment X3. I've been wanting to get an Ozone package and/or Wavelab. Sonar is supposed to be able to "master" stuff and it can to an extent but those are the real deal. Honestly if Sonar could do what those programs could it would (and should) cost significantly more.
 
Otherwise by some outboard stuff. Mics are super important and cost a buttload so dropping money in that kind of stuff and then learning the tools you already have inside and out is likely a better plan.
 
Sorry if that has already been mentioned. Didn't read the thread. Cheers.

Thanks KARYN
 
That is kinda the dilemma when looking for advice
 
Most people start off by saying things like "learn to use the tools you have" - but of course there is a step before this to choose what to learn! (chicken and egg!!!)
 
I also appreciate that there are different "horses for courses" and it is the same as people recommending one DAW over another - you never really know whether something will suit your needs until you try it
 
I guess I was just looking for a bit of guidance as to where to start looking and why
 
Thanks to everyone for the responses so far as they have definitely helped me refine what I am looking for (if anything)

I find the Sonitus suite (that is included with Sonar) is really the best start for learning all you need to about specific types of effects. They don't look pretty but they mostly have all the controls you will encounter on pretty much any commonly used plugin out there. If you can learn to use them then all the other fancier looking plugins (and the Prochannel stuff) will be a piece of cake. Also the Sonitus stuff works extremely well on their own. I mostly use the Prochannel stuff but fallback on the Sonitus plugs. The new BlueTubes stuff has some cool emus so I've been playing with those as well but they would be confusing if I hadn't learned the basics.
 
I highly recommend buying and watching Karl Rose's X2 Advanced FX series (or whatever it's called). I picked it up for something ridiculous like $5 at one point and it is really great for understanding how to use the included effects (even though we have a bunch of new ones so I hope he updates the series). Also I'd say a month pass at Groove3 would be a good investment then checking out the effects vids to get more general info on how specific things work.
 
Then you will have a much better understanding of what is what and why it does what it does. Could save you a fortune. It certainly has made me realize I don't need to drop any more coin on simple plugins.
 
That said the Concrete Limiter and CA2A are brilliant addons for Sonar and they go on sale from time to time. Definitely worth snagging if you don't already have them. 
 
Cheers.

Boydie....realize that in some of the suggestions, people have already purchased some of the stuff you wonder about, and realized that wasn't the real solution for improvement, although they weren't necessarily a regretted purchase.  Probably quite the opposite.  But take that as a tip to maybe save yourself some money.  To close your eyes and throw a dart and see where it lands, figure you'll learn it... offers too many choices and it's so easy to get off track and actually down the wrong road chasing quality.  The current audio market has exploded with choices as of recent, and has created a whole generation of people chasing quality, thinking it can be bought.  Well of course you need the right stuff, but tell me, which is the best compressor nowadays?  If it's hardware it could be no less than a dozen choices.  If it's software, the same could be said.  Is Cake's CA2A really that bad??  Well buy both the hardware and software and see if it is.  You'll learn.  Then $3500 later, you may decide that wasn't what your really wanted anyway and it was more along the lines of a Distressor.

But any rate...take Karyn shopping.  She's addicted.

Sonar covers the basics pretty well between Sonitus and Nomad Factory. I would look to add Soundtoys as a more creative suite. 

I have got and studied all of Craig's excellent videos, Karl's fantastic vids, and have spent the last year trawling Groove 3 vids so I do consider myself an advanced user of the existing tools and techniques
 
I am just getting hungry for some more tools to play with and I have found it more economical in the long run to "buy the best" once and invest a long time learning and growing in to it rather than keep buying bits and pieces
 
Great info and discussion though