9. As Birds Eye's Mascot On A Packet Of Fish Fingers
For better or worse, Doctor Who's Series 5 opener introduced fish fingers and custard to the world, with the recently-regenerated Eleventh Doctor trying a bunch of different foods to give his new tastebuds a trial run.
This unusual dish proved such a hit with fans that it even spawned a National Fish Fingers and Custard Day on 3 April - the day the episode originally aired - and yes, there are even people out there who've admitted to trying it for themselves.
The episode also permanently associated the Eleventh Doctor with fish fingers (it's incredibly difficult to not make a "fish custard" reference when you walk down the corresponding supermarket aisles), but even so, absolutely nobody could've predicted that he would one day end up as an official brand ambassador for the product.
In 2013, Birds Eye created a bespoke packet of fish fingers that replaced Captain Birdseye with the Eleventh Doctor. This packet was then gifted exclusively to Matt Smith - along with a 12-month supply of fish fingers. Apparently, Smith doesn't actually mind the taste of fish custard, so he perhaps had quite a lot of it that year!