In my opinion, the current hardest record to break would be the single season win record for a team, set by the Edmonton Blizzard in season 45 where they achieved a record of 41-6-3 with a goal differential of 78 on route to a Challenge Cup victory. The record involved a perfect 6 and 0 record from backup goaltender Alistar Cain and an MVP season from Tommy Tuck, who set a new record in Goals Against Average and Wins.

Apart from the goalie we also put three players into the top five all time in Plus Minus, and Tommy also scored a spot in the top save percentages ever.

The reason I think this will be such a hard record to beat is because with the talent in the league becoming deeper and deeper, super teams are becoming harder and harder to create. The season 45 Blizzard will go down as a top team of all time, and hold this record because of it.