My place has a lot of these conditions! I have a lot of drainage ditches that I clean out into mounds to plant into.
Plum trees have been the best fruit for really wet sites, even with some standing water in the winter they seem to survive. Elderberry are also pretty good there. Hawthorn is also good there and can be used as a rootstock for many pears.
Apples and pears seem to be ok a foot or two up a mound. Any mound will settle over time though so it will need added to if there is not any higher ground within 15 feet to get roots growing into.