Out of the old/extinct brands:
Expresslink
Lambton Worm brand on the Darts
Original Lime brand on the Renowns
Orange Diamond brand on the Citaros

Out of the new brands: 
Xlines branding, especially the X20 version on the Citaros
New Diamond on the Geminis

And lastly, I really want to like the new Connections 4 livery (and its growing on me!), but design agencies need to stop completely ignoring the importance of colour contrast in terms of accessibility. The 'Connections' text on the branding is a prime example: