NHL '98 / EA / Sega Genesis
As with Madden '98, EA turned over the 16-bit port duties to THQ with this installment, and as with Madden, it looks like they just looked at the previous game's engine and said "good enough as it is." They swapped out the title screen graphics and rearranged the menu slightly, and updated the rosters to the outset of the 1997-98 season, but other than that, this is really the exact same game as the '97 installment.
With Madden, that was more of a flaw, because there were still a boatload of problems with the game that could have been addressed, and improvements to the gameplay that could have been made. The NHL series, on the other hand, was already about as good as it was going to get on 16-bit consoles. Were there some minor tweaks that could have been made? Oh yeah. For one thing, the same limited season mode - where you pick only one team and play only their games for the duration - returns again here, perhaps the one significant weakness of '97. You'd also like better (more thorough, not just a handful of categories) seasonal stat tracking, maybe more of a reward for winning the division and Stanley Cup. And some new music would be nice, after playing a full season in NHL '97, I really didn't want to hear the same shitty techno all over again. There's a richer pipe organ sample that plays the appropriate national anthem at the beginning of each game, but don't let it fool you into thinking the organ work is awesome now, once you get in-game it's the same old little tunes you heard all through the last installment.
Still and all, I guess a good clone of a good game is still basically a good game. It'd be more egregious if there was more room for improvement, but this is really the pinnacle of hockey in the 16-bit generation.