The Dems had a good night. Some of the media stars didn't win and you can say Trump message of fear beat out Obama message of hope when you look at very specific races but overall, the Dems won where they needed to.
The House is the big win but some of the smaller wins include Wisconsin Governor's house, flipped 6 other governorships which is huge in a census cycle, won a house seat in the middle of OK and FL will add 1.6M to its voters’ rolls.
But turning back to the house, there will finally be a check on what Trump does and says. He will be reigned in on his far right agenda and his corruption allegations will get some public light which will come into play in 2020. At least 18 Republican senate seats will be up in 2020 so there is a better chance of a flip then. The GOP flipped the two houses in off-year presidential elections making this house win is just like how the GOP started their takeover in 2010.
So the Dems did what they had to do this election cycle. Their next task is to hold Trump to one term; something the GOP was not able to do to Obama.