To make the list, games must have:

Varied Offensive Options
Defensive Depth
Grounded Movement and Tactical Positioning
Good Pacing
Skill Expression
Organic Challenge
Varied Movement Options
Refined Combo System and/or Neutral Play
Environmental Interaction
Replay Value and Extra Modes
Dynamic Combat Elements
Impactful Strikes and Feedback

Genres I'm using: beat 'em ups, roguelikes, brawlers, character action, hack & slash, punchout clones, action RPGs, and fighting games... although to a limited degree since, they are too personal and have too many obtuse mechanics.


Clauses:

Innovation Clause: Groundbreaking mechanics.
Exceptional Quality Clause: For games that excel exceptionally well in certain criteria.
Genre-Specific Flexibility: Recognizes that different genres may prioritize certain aspects of melee combat over others.
Case by Case Evaluation:
Emphasizes the importance of context in evaluating a game's combat system, ensuring each game is assessed based on its unique contributions and how well it embodies the core criteria.
Acknowledges that a game can be exceptional in certain areas even if it doesn't meet every single criterion, considering the overall experience it offers.
Allows for flexibility in how criteria are applied, understanding that innovation, exceptional execution in specific areas, or the successful adaptation of combat mechanics to fit a genre's conventions can all significantly enhance a game's melee combat experience.

I'm going to need way more time to incorporate every good melee game, and tend to focus on stuff with more flare first.