When I started plugin development, I kinda made a promise to myself to "never make another EQ plugin" but I couldn't resist. I'm not sure if anyone will find this useful, but it's what I've been using almost exclusively for a while now, so I figured I'd release it.
This is designed for "less is more" and comes with a pair of filters, pair of shelves and two mid-freq bells. This isn't "quite" cookbook stuff. Have fun trying to match them with a stock EQ.
Tech-wise these use a fitting method to approximate analog response, improving the high-freq shape significantly (whether you compare to cookbook or Orfanidis-style compensation). To further improve the very-high frequency response there's 2x oversampling (actually that's mostly so the high-shelf cutoff can go to 24kHz and the low-pass to 28kHz, but it also looks a bit better in a spectrum analyzer).
Processing is done with my SVF-inspired filter structure which is cheap to calculate while handling low-frequencies rather better than the average direct form filter (proper 0df SVF would be even better, but would roughly double the CPU.. I tried, but figured it's not really worth it).
The custom shelves are rather wide and quite asymmetric. They are designed such that the response is fairly flat on the "unprocessed" side, with much more gentle curve on the "processed" side. I like it that way. YMMV.
The bells are otherwise "standard" except gain is relative to bandwidth: actual peak gain is actually gain/sqrt(width) so adjusting bandwidth approximately maintains the perceptible strength of the boost or cut. It sounds complex, but I find it very natural in practice (just remember you can get more peak gain by turning down the width, if you wan to tune the bands or something).
Download (Windows only; now with experimental 64-bit version; you need SSE2)
updated 1.0.1: fixes resource allocation problem that was causing crashes when closing editor
updated 1.0.3: should fix another editor-closing crash with old Intel drivers
updated 1.0.4: GUI should open a bit faster after being loaded once; should report if SSE2 is missing
updated 1.0.5.1: fixed OpenGL problems being reported multiple times (1.0.5) and included experimental 64-bit build (1.0.5.1 - otherwise identical to 1.0.5)
Technical note: This use completely new UI toolkit so there may be bugs; please report any weird behavior. The toolkit renders with OpenGL so you need some sort of a GPU (anything post-2000 should work at least).
and because of that I probably wouldn't have reported the problem if it wasn't the exact same issue as miedex above. 
