My personal heaven: A huge tower with thousands of branching off corridors, each one lined with door-ways. Each doorway is a new small dimension, belonging to a person. Every person gets their own door. They can make whatever they want in this little dimension (complete god-like power within it), but you can never die, never age, there is no disease or sickness and you heal within a day from even obliteration. You CAN still feel pain, but it is not as severe.
You can also invite anyone else into your dimension, but they can only enter with the owner's permission. Everyone who dies old will reverse age to an age between 20 and 30 when they were best. Everyone who is younger will age forward until that point. This won't be instant, but not as slowly as here on Earth.
All positive sensory reactions will be heightened where pain was dulled, so a loving touch or cool breeze feels that much nicer and the bright colours of the glowing neon creatures you fill your dimension with will look all the more stunning... Also memory will work differently, past trauma in life will still be remembered, but not hurt as much, and good things will not get old, if you love Ferrero Rocher Chocolate, you could be well... in heaven because of them all the time. (you have to keep happy and busy for an eternity).
You will also have the door address of all your good friends, lovers and family from life, and you will remember your life.
My hell: Complete loneliness, to remain conscious in a state where there is nothing, at least biblical hell has pain, and you can still be pre-occupied. Also non-existence, yay, my own personal hell is assured for me.