Space Mountian may be one to avoid.
Splash Mountian has some big drops and some that are completley in the dark.
Big Thunder Mountain is relativley tame for a rollercoaster, you may be ok with that one.
The Haunted Manison is not really bad unless you are really frightened of dark places/loud noises etc.
Some children get scared of Snow White's Scary Adventures. It's not too bad at all, but that is from an adult point of view. It has a few dark scenes.
The Barnstormer at Mickey's Toontown Fair is ok, but is a rollercoaster, even if a very tame one.
A lot of children seem to get scared at the Stitch experimnet ride thing. It'scompletley pitch black sometimes, very noisy etc.
Only you will know the limits of your children, you may want to go through the rides first yourself to check them out (time permitting of course).
I dont think I have forgotten any, the rest should be completley ok.