Once everyone is introduced and the premise is made clear, the second season takes the series to a whole new level. The closing moments of the last episode from season one…the arrival of Rias in the Hyodo household (more specifically, Issei's bed...) foreshadows the future (harem?) drama of Rias and Asia fighting/sharing Issei while all the other females in the ORC slowly develop and realize emerging feelings for him. The growth of Issei's harem is also marked by the growth of the ORC's female members feelings for Issei.
To be fair, Issei not only saves the ladies, but is a good friend to Kiba and works towards the common good (establishing peace) among devils, angels, and fallen angels. Characters like Vali and other enemies provide us with a good amount of combat and further evolution of Issei's Sacred Gear. The animation, voice acting and overall quality of the shows still continues to be top-notch in my opinion.
If I had to pick one thing that wasn't all that great in my opinion...Gaspar. A freshman, half-vampire transvestite whose primary use would seem to be able to stop time....so that Issei can peek and grope the time-stopped female baddies. Almost like a throwaway character. Developing Irina, for example, could have been a better use of screen time. Then again, Rias had to have another bishop to complete her household and Irina is firmly in the angel camp and not going to be a devil any time soon.
Favorite moments include Sir Zechs/Lord Gremmory/Rias family sleep over at the Hyodo home in "Open House Begins!" and the Vali-Issei fight at the end of episode 24...and the whole female contingent of ORC having to move in with Issei. The season ends with it looking more and more like Issei has assembled his own harem....
Season 2: 10/10