From the teams I follow closely:
London: Evan Bouchard looks really good, top 15-20 if he keeps this up. Foudy and Moskal are off to slow starts, but if London turns things around either could be a good late round pick for center depth, if not higher than that. Otherwise, could be good options for a D+1 if they turn things around next year. Same goes for Whittaker on the wing, Kooy in net and Regula on RD. Kooy has a ton of skill for someone his age, and if he falls due to London having a poor season and an even worse defense, then that could be a major coup for the Leafs.
Sherbrooke: Nothing really worth getting excited about. Alexeyev could be a good undersized playmaking wing addition in the later rounds. Having another pretty good year in his D+1. Other than that, Anderson MacDonald, who was dealt to Moncton, looks like he may fall to the 2nd round but he's a great scorer (29 goals as a rookie on a weak team) and has size. Could be a top 6 PWF/SNP type.
Sault Ste. Marie: Barrett Hayton looks like a top 60 center prospect, possibly even in the top 30-40. Haven't seem much of Sandin, but he's supposed to be a late 1st/early 2nd defensive prospect as well.
Saginaw: Blade Jenkins has struggled since being a top draft choice, but could turn things around and be a worthy late round pick. Damien Giroux is an undersized center/wing who looks like a late 3rd round pick/early 4th round pick. He's doing pretty well.
Spokane: Filip Kral looks like a 2nd round quality defenseman. Maybe drops to the 3rd round, but he's got skills. Ty Smith could go top 10 or even top 5. They've got some other decent 2000's who could be taken in the later rounds, but are more likely to be taken as a D+1 if they have a good follow up year like the guys in London. They also have some 99's who may be worth a pick in the late rounds, like Weatherill (went to SJS camp) and McIndoe (who we invited to camp).
Prince Albert: Cole Fonstad looks like a 3rd rounder as a smaller center/wing. Otherwise, a few 00's who are struggling but may turn things around and a few 99's on defense who may be worth a late round pick.
As for NCAA guys drafted by these teams: Johnny Gruden is a 3rd round winger to me. Scorer, average or slightly below average size. You see a lot of those types of guys go in the 3rd round. Gavin Hain is a 2nd-4th round center prospect. 5'11" but skilled. Jacob Goldowski may be a 5-7 center prospect. Bode Wilde is a top 10-15 pick. Mitchell Morrison and Tyler McBay may get late round consideration. Tkachuk is considered a top 5 prospect. Dominik Bokk (CHL Import Pick) may be a 2nd/3rd round winger prospect. Jacob Semik is rated as a 2nd round defensive prospect, but I think he'll end up being taken in rounds 3-5. Peter Muzyka may be a late round pick.