IDK, I think I will agree to disagree:
- 3e: The start of the WotC era.
- Eberron was pretty interesting / innovative. Not my preferred style of D&D, but interesting and better thought out than a lot of 2e settings
- 3.5 draconomicon is the gold standard for TTRPG dragon books IMO
- Standardizing on the d20 mechanic was a nice innovation
- OGL was a huge impact and was definitely an innovative idea for TTRPGs
- Probably a lot of things I am not thinking of because I didn't play this edition.
- 4e: I also think 4e as whole was extremely interesting and innovate in both lore and mechanics. I think it may even be near a high water mark for TTRPGs since the founding of D&D.
- Dawn War and general cohesive mythology/cosmos
- Nentir Vale setting
- AEDU powers design & class balance
- Class roles
- Divorcing Monster design from PC design (really this harkens back to TSR era design).
- Monster design in general, but...
- Monsters by level and type (minion, standard, elite, solo)
- Monsters by role (brute, leader, controller, etc.)
- Iconography
- 5e: I think there are a lot of interesting and innovative things with 5e too.
- Advantage / Disadvantage
- Bounded Accuracy (more the idea than the implementation)
- Legendary and then Mythic monsters
- First World
- Radiant Citadel (more the worlds it opened up than the citadel itself)
- DnD Beyond
- Edition based canon
I'm not a boycotter in general unless it is something of real importance, and TTRPG companies do not qualify IMO.