Lilydale is not real great. I've seen a lot of cars broke in there. ramp is in not in a no wake, no docks, and not really a beach to hold your boat at.
Hidden falls is a decent ramp but the current is REALLY strong.
Fort Snelling is probably the best in the area but is not free.
I really like SSP under 494 bridge. Current is not TOO bad, dock, free,
Then there is Newport which is in some backwater. No current, no wake, dock, free, Just really muddy around the ramp and not much room to move around.
The marina in the no wake zone near fort snelling on the Mississippi has a really nice ramp but we have never used it and I am sure it's not free.