The Tom Vac chair by Vitra is one of my favorite plastic chairs, but alas its quite a bit more expensive than my 100$/chair target. What we did was to get just two of them, to put at the ends of our meeting table, and used less costly color matched chairs for the rest.
The Tom Vac was designed by Ron Arad and introduced by Vitra in 1999. Its got a far out swoopy look, but its also very practical in that it is a stacker (you know, a stacker is a chair that nests so they can be stored stacked up). It is not an arm chair perse, but is a big bucket shape that reminds me of the Eames fiberglass shell with arms. Like the Eames chair the Tom Vac is offered with alternate bases in other markets (sorry USA, not available). You can get a rocker base - Tom Roc, or a task chair base with casters - Tom Roll. I know, corny, clever, and fun.
So while it may be a bit much for a full set of chairs, both cost wise and visually, it makes a good highlight to your meeting setup.