My next purchase?

Hi guys, so I've recently come to discover the absolute joy of being able to just drag a monster onto my game instead of having to manually input statistics for everything. I currently own the Monster Manuel, Volo's Guide to Monsters, Mordenkainen's Tomb of Foes.  What would you recommend my next purchase should be for a nice big list of new monsters? 

Kobold Press has two Tomes of Beasts and a Creature Codex. There's a bundle on the Marketplace, but that's still a pretty big chunk of change. Mordenkainen Presents Monsters of the Multiverse has a ton of monsters, but the preponderance of them are updates to monsters you already own. It's up to you if you want to stay current, but it also has updates to a bucket of PC races, gathered from many different sources.

Here's a list of each compendium book and the number of monster statblock each one provides (though I haven't listed a couple of adventure modules I don't have, I don't expect them to have many unique statblocks). I would note that some of these do overlap and provide the same things - eg. adventures usually provide the statblocks for monsters used in the adventure even if they're already in the Monster Manual. 450 - Monster Manual 422 - Creature Codex 410 - Tome of Beasts 403 - Tome of Beasts 2 324 - 5e SRD 290 - Mordenkainen Presents: Monsters of the Multiverse 247 - Mordenkainen's Tome of Foes 138 - Volo's Guide to Monsters 85 - Odyssey of the Dragonlords 85 - Guildmaster's Guide to Ravnica 77 - Fizban's Treasury of Dragons 63 - Rime of the Frostmaiden 60 - Margreve Player's Guide 57 - Ghosts of Saltmarsh 53 - Eberron 51 - Mythic Odyssey of Theros 51 - Baldur's Gate: Descent into Avernus 47 - The Wild Beyond the Witchlight 46 - Humblewood 45 - Strixhaven: A Curriculum of Chaos 45 - Critical Role - Call of the Netherdeep 38 - Tasha's Cauldron of Everything 36 - Van Richten's Guide to Ravenloft 36 - Essentials Kit 31 - Explorer's Guide to Wildemount 27 - Lost Mine of Phandelver 27 - Candlekeep Mysteries 25 - Dark Matter Starter Kit 24 - Acquisitions Incorporated 22 - Tyrany of Dragons 9 - Dungeon Master's Guide 5 - Underworld Player's Guide 4 - Deep Magic 1 - Xanathar's Guide to Everything 0 - Wardlings Campaign Guide 0 - Tales from the Yawning Portal 0 - Sword Coast Adventurer's Guide 0 - Southlands Worldbook 0 - Southlands Player's Guide 0 - Player's Handbook 0 - Out of the Abyss 0 - Midgard Heroes Handbook 0 - Empire of the Ghouls 0 - Class Modifier Module Like Keith mentioned, for $120 you can get the Bundle of Beasts which contains 3 compendium books and 1235 new unique monsters in total. That gets you as many monsters as basically everything else put together (considering the SRD is free and Monsters of the Multiverse is all things duplicated in other books too). Hopefully, this list will help you figure out how to get the best bang-for-your-buck if you're after new monsters.

Great list, Liam! That looks like it was a ton of work.

Not at all, just a lick of Javascript to flip through the filters in the ingame compendium and count the number shown for each one. Thought it'd be interesting to know too!

That's a great reply, thanks a ton Liam!