PBL has the best prices no doubt.

In general, I use PBL's 3-LEDs on colored inserts; to avoid the blinding effect, I like to stay with incandescents on white inserts. Also like PBL white 3-LEDs in my backboxes with the occasional use of 3-LEDs behind certain translite elements (green for MB's haunted house & purple to highlight the horizion).

CT's flex 555s/44s rock for pinpointed insert lighting. They also have some great specialized stuff for some really cool effects: red 9-LED 906s for backbox explosions in AFM; white 13-LED 906s for a better lightning effect in TAF's topper to name a few.

BCS has some rare colors: turquoise in 555s & 44s...those look great in a few places--selective GI PF placement in WH2O comes to mind.