If you think Tanaka is that great give me some of her good roles and i'll check them out.
Anyways, I've always felt that Hayashibara is overrated, although that's largely because she gets typecast in the same type of roles. The couple of different roles i've seen she did well, but I still think she gets too much credit.
Inoue is another one who gets typecast alot, but when she gets a role that isn't a Yamato Nadesico archetype or something along those lines she's actually really good. My favorite role of hers is probably Electra from Nadia.
Tamura I can honestly say i've never seen her in any sort of a standout role. If you want to point a couple of good roles for her out to i'll check them out.