My favorite was when I was playing as a SMN, I had what could only be called the most inept tank ever (Pre-SHB changes). He couldn't hold aggro to save his, or any other party members life, so I put away Garuda-Egi, and brought out my Titan-Egi, My Egi tanked the entire duty, including all 3 bosses, the tank actually quit after the 2nd boss, leaving just me (the SMN, the Healer (which I believe may have been an SCH) and the other DPS.. I really don't remember what the other DPS was... ROG/NIN or LNC/DRG I think). My most memorable rant worthy moment, funnily enough, by the end of it, I was so proud of myself for DPS'ing and Tanking at the same time that it didn't bother me, though I did share the encounter with my FC of the time after the duty concluded.