Updated with a new list I found, I just got a new mac, so I'm finding many updated lists of "free AU and VSTs for 2014-2015.
Some of these are fairly new and look pretty neat-o enjoy!
[Only registered and activated users can see links. Click here to register] (mac & win)
-----VST / AU Available-----
Effects
Nova-67P ( VST/AU | Win/Mac | 32-bit & 64-bit )
TDR Kotelnikov ( VST/AU/AAX | Win/Mac | 32-bit & 64-bit )
SlickEQ ( VST/AU/AAX | Win/Mac | 32-bit & 64-bit )
SGA1566 ( VST/AU | Win/Mac | 32-bit & 64-bit )
Multiply ( VST/AU/AAX | Win/Mac | 32-bit & 64-bit )
SlickHDR ( VST | Win | 32-bit )
Hysteresis ( VST/AU | Win/Mac | 32-bit & 64-bit )
Faraday Limiter ( AU | Mac | 64-bit )
BTQ2 ( VST | Win | 32-bit )
Saturation Knob ( VST/AU/AAX/RTAS | 32-bit & 64-bit )
SquashIt ( AU | Mac | 32-bit & 64-bit )
Amplio 2 ( VST | Win | 32-bit )
Atom ( AU | Mac | 32-bit & 64-bit )
FilterCrusher ( VST/AU | Win/Mac | 32-bit & 64-bit )
Red EQ ( VST/AU | Win/Mac | 32-bit & 64-bit )
Instruments
Dexed ( VSTi | Win/Mac/Linux | 32-bit & 64-bit )
OBXD ( VSTi/AUi | Win/Mac | 32-bit & 64-bit )
BrainStormer ( VSTi/VSTi3 | Win | 32-bit )
Lokomotiv ( VSTi/AUi | Win/Mac | 32-bit & 64-bit )
Tunefish 4 ( VSTi/AUi | Win/Mac | 32-bit & 64-bit )
Avatar ST Pro ( VSTi | Win | 32-bit )
Scylla ( VSTi | Win | 32-bit )
Nabla ( VSTi | Win | 32-bit & 64-bit )
MT Power Drum Kit 2 ( VSTi/AUi | Win/Mac | 32-bit & 64-bit )
Korzenie Kick ( VSTi | Win | 32-bit )
BigRoomKixSynth ( VSTi | Win | 32-bit )
Ragnarök ( VSTi | Win | 32-bit & 64-bit )
SynthMaster Player Free ( VSTi/AUi/RTAS | Win/Mac | 32-bit & 64-bit )
M-theory ( VSTi | Win | 32-bit )
VS Upright 1 ( VSTi/AUi | Win/Mac | 32-bit & 64-bit )
Guitar Amplifiers
Grind Machine Free ( VST/AU/AAX/RTAS | Win/Mac | 32-bit & 64-bit )
Emissary ( VST/AU | Win/Mac | 32-bit & 64-bit )
Flextron DC14 ( VST | Win | 32-bit & 64-bit )
Ace ( VST/AU | Win/Mac | 32-bit & 64-bit )
Boogex 2.0 ( VST/AU | Win/Mac | 32-bit & 64-bit )
Utilities/MIDI
Minihost Modular ( VST/AU | Win/Mac | 32-bit & 64-bit )
A1StereoControl by A1AUDIO ( VST/AU | Win/Mac | 32-bit & 64-bit )
Instretch ( VST | Win | 32-bit )
CCStepper ( VST | Win | 32-bit & 64-bit )
Sturiophonia ( VST | Win | 32-bit )