Depends on if I need the space and if the sequel uses the old save data.

Usually I let it linger in the memory card and if I need space later, I will delete games that there is no chance of going back too.

If the game wasn't enjoyable enough for me to eventually come back in a drunken stupor, or a fugue of nostalgia, then I would delete my save files. If there is redeemable value, but I have just played the game so much that all the fun has been leeched out and only a desiccated shell remains, then I would probably hold on to the save files just in case I wanted to leech on it some more in the distant future, like the year 2000 or something.

I usually don't unless I hit the limit on my memory card. Except the PS2, I've never maxed out a card before. I managed to fill my Wii memory, but I got a 1Gb SD card to move things to.

If it's a game that I've gotten really bored from then yes, otherwise I might pick up where I left some other time or I might remove the saves when/if I want to play it again...

Yus. Why would you clutter your hd?

I only delete when I need space for a new game & I figure I'll never play it again, or it's a game that's easy to get through

Depends on if i need the space, or if i've already sold back the game xD

it depends on if there are side quests, or if i have REALLY rare items, or things of that nature.

Have yet to ever do that lol