Well if we're going to start coming up with different grades of angel, we can at least use the thousands of years' worth of existing terms. The level above "Angel" is "Archangel".

Then it's Principalities, Powers, Virtues, Dominations, Thrones, Cherubim and finally Seraphim (the exact order can vary, but I'm going with Dante).

That should provide enough fuel for angel-on-angel one-upmanship for now. (If not, we can move on to the Jewish angelology, which includes four additional ranks above Seraphim.)