Some of this has already been mentioned. I'll stick to freeware thoughts too.
(1) EQ
The mixer EQ could be more of a useful channel strip? With Q control.
And the excellent GLX4070 is consigned to ProStudio, how many folks use this? I do.
Similarly, the TB Parametric in ProStudio is perfectly fine, but is not made obvious.
Some of this comes down to how Mixcraft forces you to do your own organisation of the Plugins.
TDR Nova is the Fabfilter freeware beater here. It has a brickwall hipass, Dynamic EQ, and spectrum analyzer. Great stuff.
Low and High Pass metering is sadly lacking currently, as I personally don't care for the clip level implementation. The ProStudio only TB Parametric is reasonable here, but only TDR Nova (or Fabfilter - payware) offers 72dB brickwall.
It would make most sense to build this into the channel strip direct perhaps.
(2) MASTERING
TDR Nova again, but also those things that add character/console emulation eg the Klanghelm products
IVGI and
DC1A are excellent.
There is an excellent EQ from TDR labs called
TDR VOS Slick EQ and it really does add character, but perhaps more useful at the mastering stage.
(3) COMPRESSION
Limiter no.6 has been mentioned, and this gives excellent multiband limiting (see also Mastering) which can be unlinked.
MJUCjr is also an excellent characterful compressor. I haven't had much luck with the valve, tube etc etc compressors built-in to ProStudio tbh.
TDR Kotelnikov is also excellent for mastering, and very smooth, with a configurable hipass, but those who are desiring those pumping effects I guess are waiting for the native side-chaining....
Final callout for the excellent Toneboosters stuff, eg
TB Barricade as a Brickwall limiter (which can be scary) it's subtle and ace when used right. This contrasts I think with the Kjaerhus stuff built-in which is less useful.
(4) REVERB
I'm open to Freeware suggestions here, but I would say that the Acoustica Pro and Fusion Field are both very good, but again consigned to the ProStudio product.
(5) PITCH and VOCALS
A cutdown Melodyne version? Gsnap calls itself "state of the art", but it really really isn't. I purchased Izotope Nectar Essentials (grudgingly), but am sure many other folks have good ideas here (I could never got on with the zPlane one).
(6) METERING and OTHER
We all miss metering I think. And probably start with
Span. I've not actually gone out and purchased better, but I really wish I had some Loudness metering, instead of having to measure LUFS and all that stuff after I've rendered the final mastered WAV. Ah well. So, even something like Span built-in would be better than nothing, eh?
Transient control and colouration is an interesting one, we've all messed around with the Pultec (but found it hit and miss perhaps and CPU heavy), but how many people know how good the Treblecream and FAT++ (both Prostudio only) actually are??
Because - they're hidden within the mass of other VSTs I feel, unless you manually and painstakingly get organised.