So many pieces that are decent for PLD... it really depends. Just off the top of my head these are good ones, for tanking.
Homam - Legs ,Hands - Feet for /nin(Ni)
AF1+1 - Body ,Feet - Bolded is a pointless upgrade unless you have nothing else to spend coins on, and cannot sell them as it adds no enmity, and very litte HP. Epeen item only imo.
AF2 - Body ,Hands ,Feet ,Legs - Head is also useful to macro in for Rampart as it extends duration.
M abj - All - Head should be a priority for shield skill+, the rest has extremly limited uses.
Iron Ram- All can be used, just not on at the same time unless you need the magic defense. - Excellent set, especially for a new 75 pld, and easy to obtain. MDB, high Enmity+, HP+ on each piece and the set bonus, very nice.
Ares - I think all can be used, I dont really know the stats though other then body. - Body is good for a standing set, the rest is trash for pld
W Abj- Legs - Must have item for *most* kited battles
Askar- Hands ,Head - Feet are excellent again, head no, Wally Turban has an additional +1% haste and 30HP/MP, better in every way for Ni casting, and easier to obtain.
(Pretty much what jakey said)