Beano as a nipper, then Warlord, Victor, Battle/Action from about age 7... I can't remember which is which now, but still remember some of the storylines.
Was it Victor which used to have a true story on the back page, with comic strip account of VC-winning actions etc? Very inspiring and a great recruiting tool lol... There was also a weekly with a lad who used to climb sheer rockfaces (barefoot?) to ambush the jerries / eyeties / japs from behind. Union Jack Jackson has already been mentioned.
Non-war, used to read Tiger - Hot Shot Hamish, Billy's Boots and other sporty (invariably football) titles. Hamish had a shot like a rocket but he was ******* inaccurate - used to knock down goalposts, floodlights, passing airliners etc. Billy's Boots was about a shit footballer kid who has a pair of crappy old falling-apart boots which belonged to his old idol (something like Deadshot Kean?), which turn him into an amazing player. He usually loses them about once a week. Plays like shit until his mum turns up with the old brown boots, whereupon he can suddenly turn the game around. It's a bit like encouraging kids to cheat & take illegal performance-enhancing drugs in order to win at sport.
Oh, and Roy of the Rovers of course. I think some football game (Sensible Soccer?) even introduced Melchester Rovers as a team on there. And I have a vague memory of a comic called Hotspur, but I might be mis-remembering.