Pasadena is not so great for falafel. The ones at Zankou are all right if you manage to get them fresh, but most of the time, they come from under a heat lamp.
If possible, I'd recommend the drive to Skaf's in Glendale.
I would avoid Pita Pita and (especially) Mediterranean Cafe. Pita Pita used to be all right, but they really seem to have gone downhill in the past few years. There's a Pita Jungle in Old Town; haven't been to this location, but I've tried one of the AZ locations a long time ago. My guess is that this is also worth skipping.