Only for a limited time, so grab this while you can! Get it here! 
You will need an account there, but it’s worth signing up for one!
U-he Zebralette
(Click here for download info)
Just got this and haven’t had much time to play with it, but was amazed at it from even the little time I spent with it. Worth it! Get it!
(the Windows version appears to be VST only, so you will need the FXPansion VST-RTAS wrapper if on Windows.)
Komplete 8 Players
(click here for download info)
A collection of Native Instrument’s free players that includes:
Reaktor 5 Player
Guitar Rig 5 Player
Kontakt 5 Player
(click here for download info)
Very much like the IKMultimedia Sampletank Free, the Kontakt Player is a free plugin that allows you to load samples in multiple formats. It comes with a basic sound library, but you can purchase sound expansion sets, and even find some free samples to load and play. This is one of the only sample players to load and play SoundFont samples, so this is worth grabbing just for that.
Many “Kontakt” samples that you might find for purchase require the full blown version of Kontakt (a plugin that I do recommend) to be played, so that is something to consider, but this will work as a free plugin very well.
Alchemy Sample Player
(click here for download info)
From the website:
“A free software instrument with an inspiring 1GB sample library and 200 instrument sounds including evolving soundscapes, lush pads, and pulsing arpeggios. 150 sounds are included with 50 more when you sign up for a free account.”
Decent plugin (awesome for free!) and it will load SFZ sample libraries.
Blue Cat Audio Triple EQ
(click here for download info)
If you’re not interested in the whole Blue Cat Free Bundle, you can get this individual plugin from their website.
From the website:
“A 3 band semi-parametric equalizer that can be controlled like a single filter with customizable shape.”
Free. EQ. FreeEQ.
Blue Cat Audio Phaser
(click here for download info)
If you’re not interested in the whole Blue Cat Free Bundle, you can get this individual plugin from their website.
From the website:
“Modeled after vintage analog phaser circuits, Blue Cat’s Phaser reproduces this old vintage phasing effect that you can find on so many recordings, but with the precision of modern digital processing techniques.”
Phasing. Free. ’nuff said.
Blue Cat Audio Gain Suite
(click here for download info)
If you’re not interested in the whole Blue Cat Free Bundle, you can get this individual plugin from their website.
From the website:
“This plug-in suite is a series of gain utilities which let you control the volume of one or several audio tracks in real time.”
Some unique features include advanced automation through MIDI control, plugin instance link, and mid/side capabilities.
Did I mention that it is FREE?!?