Diodow by HrastProgrammer
Unconventional digital modeling synthesizer released by HrastProgrammer. It comes with no presets but it has its own kind of sounds/textures.
windows
TAL-BassLine by Togu Audio Line
Excellent Roland SH-101 emulation. TAL-BassLine is a plugin with a unique -18dB resonant filter, released by Togu Audio Line. It features an arpeggiator, LFO, MIDI automation and comes with 23 presets and a tutorial.
Iowa Trumpet by bigcat Instruments
Trumpet instrument distributed on bigcat Instruments blog, available as plugin for Mac and PC.
Electric Guitar VST: Lethality by Iridium Iris
Lethality is an electric guitar VST released Iridium Iris, suitable for alternative and rock genres, with open and muted power / octave / refused chords and open and muted single notes.
Roland TR808 emulation: VR-08 free by Alipapa
VR-08 is a free and close tR-808 emulation released by Alipapa, built around whopping 2134 samples.
Nabla by Full Bucket Music
KORG DL-50 (Korg Delta) freeware simulation, develope by Full Bucket Music. Great retro synth strings and fat bass synth tones. In addendum to the original machine, Nabla features a phaser, a delay and true polyphony.
SFZ sample player – sforzando by Plogue
SFZ sample player released by Plogue with a single instrument slot. It comes without effects.