Which two spacecraft have spent the longest times in libration point orbits? (Lagrange points, Halo, Lissajous, etc.)

Question

Libration point orbit is a general term including halos, Lissajous', and a whole zoo of others associated with Lagrange points in three-body systems.

Which two spacecraft has been in such an orbit the longest?

I specify two because I have a hunch one of the two is SOHO and I'd like to know about another.