There is a great tragedy in the coins of Gallienus. The best ones are the zoo series but they tend to be poor metal, poorly struck and raggedy if not just plain ugly. There are other mints and years with nice coins that might be described as boring. Finding the one in a thousand high grade, full legend zoo coin will take some effort. These two are my best but they are far from perfect. This lion is not part of the zoo. Zoo coins will have a legend dedicating to a god (Apollo, Diana etc.) but my lion is dated and from an eastern mint. It is unlikely you will find a real zoo issue on that kind of flan.
Like Doug mentioned, all the above posts are scarce 'eye-appeal' examples...some of the best I've ever seen.
My best gallienus. Love that its a heavy weight and real good silver to boot. Gallienus (253 - 268 A.D.) AR Antoninianus O: IMP C P LIC GALLIENVS AVG, Radiate and cuirassed bust right. R: IOVI CONSERVA, Jupiter standing left, head turned right, holding scepter in right and thunderbolt in left. 5.1g 24mm RIC 143F (Rome) Sear 10237