Tekken 7, Mortal Kombat 11 and Soul Calibur 6

1. FPS: Huge value during PS360 era where almost all shooters were in 60fps, but after 75 billion of Call Of Duty and Battlefield games, the genre became very repetitive and unapealing
2. Battle royale TPS: I don't need to explain why I think
3. Games with a so-called "solo campaign mode" which is just an excuse to charge 60$/70$ for the same old online mutliplayer game

Sports games 

FPS

Racing Games

protip: if you lead with "3 of the worst..." that will be understood as referring to quality or subjective judgement...
if you mean worst selling that would usually be explicitly stated so as to not be confused with the above.
you seem interested in sales as focus of good/bad, which is fine and reasonable for site nominally about sales,
but that is why most responses have different perspective focusing on quality and not caring about sales numbers.

Personally for me I'll say:
1) Sport - Unless there's a wacky or creative take on it (thinking Mario Strikers here) I cannot be arsed with any of the "realistic" ones.
2) Schmup - For whatever reason I could never get into these, I find them fun for a bit and then get bored.
3) FPS - I actually really like some old school FPS games but this genre has become so repetitive I can't remember the last one to come out that I've actually enjoyed.

I saw the OP said Education games but I just don't really factor these in, they are more edutainment than gaming which is like a sub-category for me.

I know it's not exactly a genre... but I find most western RPGs incredibly boring and with very lacking and clunky gameplay (mostly the combat). Everyone talks about how The Witcher 3 is one of the best games of the last gen... I just don't get it. It controls like shit. It's not fun to play at all xD

Same story with The Elder Scrolls, Dragon Age, Divinity... you name it.

Racing Sims
Sports games
Whatever genre Minecraft is.

if you were referring to sales, lately i'm not that knowledgeable about how sales have been doing but i guess as you say:

1.- Educational, teaching or didactic games.

2.- I will go with puzzles or similar, despite having some great representation and refinement from time to time with amazing games, they act more as support between the release of "bigger games" despite being one of the most succesfull and popular genres in the first generations with milestones like tetris, columns, pacman, and others that were the basis for consoles being succesful, same happened on mobile phones they were the start of popularity of gaming on smartphones with games like angry birds, plants vs zombies, cut the rope, later being replaced by clones of console games, then replaced by games like fortnite and moba games, and now being replaced by gacha/lottery rpg games.

3.- Lastly i will go with things that are like board and casino card games i don't think there are a lot of people now truly excited about playing virtual monopoly, or other hasbro like board games, or chess, poker, blackjack, mahjong etc., for them to have a little more to offer they sometimes implemented variants and some stylish differences like a story mode from a pool game i remember from like 30 years ago, where you needed to beat a cast of colorful characters each with disctinctive playstyles, but i guess lots of these games got stuck in the ms-dos,windows 3.11-windows 95 era.

as for the ones i personally don't like

1. i will go with gord 352 first option "Sport - Unless there's a wacky or creative take on it (thinking Mario Strikers here) "
2.- Mobas mostly because LoL made a surge of a ton cheap, unimaginative clones be "the standard" of these types of games.
3.-i'm picking the third one i put before, if "normal" realistic sports have a lot of problems for me, things trying to emulate "games" that i wouldn't play in reality like hasbro board games, casino games,

1. Battle Royale
2. Battle Royale
3. Battle Royale

(2. FPS, 3. Sports games)

Sports
Battle Royal
Hentai games that require you to solve puzzles. Like shit, I am horny and these devs expect me to think?