Tom Paris tends to get himself in trouble when he lets his ambition get ahead of him, not so much because he makes bad decisions, but because bad things happen when he doesn't adequately consider the risks involved. (That's probably the difference between him and Nicholas Locarno, too.)
Case in point (other than "Threshold," a gem that's thrown in the scrapheap by most fans) is "Alice," where he gets the opportunity to test a radical new navigation system that in typical sci-fi fashion totally backfires, an artificial intelligence that turns evil. (It's a wonder that the crew wasn't paranoid about The Doctor pulling this sort of thing. But it never came up. About the only Doctor story Voyager didn't do.)
You don't need to see this one for any other reason than it reflects the tendencies of Paris. Not his best moment and actually a bit of a backslide for him, actually, perhaps evidence that this grease monkey will always need paying attention to. B'Elanna, definitely pay attention.
franchise * series * essential * character
Memory Alpha summary.