Not an especially rare or valuable type for Philip, but I like this one for its historical significance.
Philip I "The Arab"
AR Antoninianus
IMP C M IVL PHILIPPVS P F AVG P M, Radiate draped bust right
PAX FVNDATA CVM PERSIS, Pax standing left, holding branch and scepter
Minted 244/245

The young Gordian III died under unclear circumstances in 244 while on a campaign against the new Sassanian emperor, Shapur I. Whether by vote of the Army or his own machinations, Philip was immediately declared emperor. A provincial citizen, he knew that he needed to leave at once to consolidate power. He reached a treaty with Shapur I on humiliating terms; he returned Armenia to Sassanian control, and paid 500,000 gold Aureii to Shapur for peace. This not only put enormous strain on an economy already on the brink of collapse, but also demoralized many within Rome, worsened when taxes were increased to resupply the imperial treasury. Philip tried to placate the populace through the minting of this coin, along with several other reassuring themes. He also spent lavishly on the Secular Games for Rome's 1000th birthday in 248. Discontent boiled over, and usurpers started coming out of the woodworks, culminating in Philip's defeat and death at the hands of his former ally, Trajan Decius.
While the Romans glossed over the events of the treaty made with the Sassanians, Shapur commissioned a monument of the event at Naqs-e Rustam:

Shapur, on horseback, holds the bound Valerian while Philip kneels in supplication. Further reading:
http://www.livius.org/pictures/iran...of-shapur-i/