I don't think we can really include Forest as a tough game mate, there are 18 other better teams than them currently!
Newcastle are below us and average, Man U aren't they good either. I think the likes of City, Arsenal, Villa, Brighton, Palace and even potentially Sunderland (away) are tougher than most of the teams you've mentioned.
With the exception of Arsenal, all of those games are winnable, and Is be disappointed if we didn't win against Forest. I don't really care how many gazillions they've spent, football is played on grass, and they've not been very good.