Update:
1. Bob the dog - ISIHAC Theme 2. Chalky - Coronation Street 3. HB - Some Mothers Do 'Ave 'Em 4. Raak - Thunderbirds 5. Kim - The Archers' Theme 6. rab - Roobard and Custard 7. Bob the dog - Pomp and Curcumstance, Edward Elgar 8. Lib - Blind Date 9. ZK - Dangermouse 10. penelope - Blue Peter 11. Watty - Porridge 12. Kim - Tom & Jerry [Fred Quimby version] 13. Herr Bratsche - Monty Python 14. Raak - Star Trek 15. Bob the dog - Dr Who 16. rab - Have I Got News For You 17. Darren - Bergerac 18. Chalky - The Sweeney 19. Darren - Rentaghost 20. rab's plang-chonger - ???

[Darren] Nope. A hint?

No 21. Another TV theme. 80's/90's.
Do-dooo,do-do-do-do-do-doooooo
La-laaa, la-la-la-la-la-laaaaa-la [repeat lines 1 and 2]
Da-daaa-da, da-daaaa-da, da-da-da-da-da-daaaaa,
Da-daaa-da, da-daaaa-da, da-da-da-da-da-dahhhhhhhh, bom-bom-bom.

[Dazed5 - number 21] It's Blackadder. [rab - number 20] Yes please.

Number 22. Yet another TV theme from the 80s.

dum-diddliddle-dum-dit-dit dum-diddliddle-dum-dit-...
dododummydummydummydummy-dooooo-do-doooo
do-diddliddliddliddliddliddle-doo-doooo
dododummydummydummydummy-dooooo-do
dodiddliddliddle-dee-dee do-dooo
do-do-do-dooo dee-dee-dee-doooo
dee-dee-dee diddliddliddle-doo
do-do-do-dum-doo do-do-do-dooo-dooo, dee-deeeeee
dum diddliddliddliddliddliddliddliddle.... etc.