Thanks Chris. I really appreciate this.
According to my knowledge that there are more than 350 elementry/primitive (nuclear/subatomic) particles, and they are being called as Particle-Zoo.
All of them have less than micro-sec decaying time (life-time) except protons/anti-protons [!], which are under debate [but mostly they do decay after 150s, or near].
Neutrinos are stable, I haven't heard rather than this. Quarks, not get isolated theoretically, or at least experimentally/physically, constitute hadrons (mesons/baryons) which decay mostly as mentioned before.
With respect to nucleons, as totally believed now, they exchange electrons (/neutrinos); protons and neutrons are, and that is why there is no problem of stability.
Electrons, positrons, neutrons and anti-neutrinos are the only known stable fundamental particles (may be protons/anti-protons). Thanks to not that even tau and muon (leptons) are unstable.