For most people, the classic '80s chorus sound is truly the Roland JC-120 amp's chorus, but for anyone not using that amp, it was the sound of the BOSS CE-1 or the TC Electronic SCF (Stereo Chorus/Flanger). Those are still two benchmark chorus pedals against which many are judged.
But not all players like the CE-1 sound -- I personally don't care for it in my rig, and prefer choruses built around delay circuits that lack the flanging or phasing effect noticeable in analog circuits like the design found in the CE-1.
If you're after that sound, though, the Voodoo Lab Analog Chorus nails it. If you want a more modern chorus sound, the BOSS CE-5 is a solid choice, and there are plenty of boutique builders putting out great chorus pedals.
We've reviewed a number of different chorus pedals at MusicPlayers.com, too, so check out some of our pedal reviews, too:
http://www.musicplayers.com/reviews/index-Guitars.php
Scott