I have heard a lot of people rip on Associated shocks.
They are proven and work excellent, period.
I built my first pair of AE shocks in 1992, and though they were a tad bit more difficult to build, it was well worth it. I only rarely changed o-rings if and when the shocks leaked, which was rare.
As for the shocks, the ones in my 1992 RC10T are no different than the ones that are in my B3, T4 or B44. The internals are identical because they work and are proven. Just my.02
As for other shocks, the Kyosho shocks have been the easiest ones for me to build, though I am more familar with the associated ones.
Original RC 10T, T4, RC8Te, Tekin RX8. Losi Ten SCTE, Slash 4x4.