Not Shaman. As Shaman there's really only two items unique to the planes:
- the (2 charge) Feign Death ring from Plane of Sky
- the Iksar Child's Tear from Plane of Fear
A very healthy percentage of Shaman (even those who raid the planes) get that last item by buying a MQ of it, and as fun as the FD ring is it's far from a necessity.
For Shaman everything else in the planes (or at least the old ones; I'm not counting PoM) is just stats gear, with better options available in Kunark and Velious.
But as for who
should go? I know those Plane of Sky haste belts are popular with a lot of folks, and of course plenty of people have epic pieces (which aren't easily purchasable as MQs) from the planes. If you're a class that needs one of those things odds are good you won't have too much competition for them, especially if you play a less popular class.