I'm partial to BG's 44K which I put in all my vehicles once a year and have been for over 15 years and I saw good results keeping my injectors clean (datalogging showed this) on my abused/raced turbo Eclipse and the piston tops had minimal carbon buildup when the cylinder head was removed at 130k miles. It's generally over $20/can but I feel it's worth it.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch