It's easy to get yourself excommunicated by the church. But getting excommunicated multiple times takes a good deal of persistence, political clout, and cash. Take Photius (b. Constantinople ca. 815), famous instigator of the filioque debate, two time excommunicatee. He was originally excommunicated ipso facto for being ordained by Gregory Asbestas, himself an excommunicatee, breaking cannon law. After a pardon from Pope John XIII, he got popped again at the Fourth Council of Constantinople for renewing his arguments over filioque and for speaking against the crowning of Charlemagne.
But his excommunicative accomplishments were surpassed by Frederick II, emperor of Germany. He was excommunicated three times. (Four, if you consider the renewal of his first excommunication a separate entity.) First he incurred the Wrath of the pope for not going on a crusade, resulting in an excommunication which was renewed for going on a crusade. The second time he was excommunicated for negotiating a treaty with the Sultan of Egypt, and finally during a power struggle with the church. Frederick II had vowed to go on crusade in order to gain the support of Pope Innocent III in his bid for election as emperor. He failed to go on the fifth crusade, delaying because of revolts in his own kingdom. He was excommunicated for this failure. In 1228 he left with a large army on the sixth crusade. However, because he left without waiting for papal orders the excommunication was renewed. Upon reaching Israel, Frederick negotiated with Melek Kamel, Sultan of Egypt, and Jaffa, Bethlehem, Nazareth, and most of Jerusalem were handed over to the crusaders. For the sin of negotiating successfully with a heathen, Frederick was excommunicated a second time. Despite the obvious spiritual pains caused by double-excommunication, Frederick crowned himself King of Jerusalem, a title held by German and Austrian Emperors until 1835. As King of Jerusalem he also married the 14 year old princess of Jerusalem and went on to found the University of Naples. He was excommunicated for good by Pope Innocent IV in 1242. His consistent flouting of papal authority and wheedling in order to be pardoned make Frederick II the world record holder for an individual with the most excommunications.
Since the Church does not publish information on record-holding excommunicatees and other such illustrious individuals in any readily accessible venue, this information is based on independent research. If another person is identified as excommunicated more often than Frederick II please inform us so that she/he may be properly honored.