I would honestly remake flawed games, because I feel that those games are in the most need of a remake.
At the moment, I am thinking of possibly creating a hack of "Silver Surfer" for the NES;
that game actually has a decent foundation, and it just needs to have some flaws fixed.
Here are a few ideas that I will probably end up using:
*autofire button, so that you don't need to press the B-button all the time
*limit the hit detection for Silver Surfer to only his actual body
*allow the player to change Silver Surfer's speed at any point
*make the backgrounds more distinct from the foregrounds;
this can be done by for example using parallax scrolling, and making the backgrounds more bluish and less saturated
(since this is reminiscent of atmospheric haze on Earth, and thus by association intuitively reminds the player that it is a background in the distance)
*allow Silver Surfer to touch everything that isn't an obvious hazard
*give Silver Surfer access to much more weapons, as well as protective shields;
this can include for example homing missiles, powerful energy blasts, and barriers that can take 2-3 hits, and the player should be able to power up a weapon into more stronger versions (without losing any attributes of the less powerful versions) by collecting it several times, as well as keep several weapons available at the same time
*give Silver Surfer access to an upgrade that lets him charge through weak walls that block a bunch of items;
this would be a little bit like the Power Suit in "Mega Man 6", except you make a fast brief flying dash instead of a charged shot
These changes could actually make "Silver Surfer" a really great game;
I will start working on something like that when I have learned game programming.