Looking for bestiary module recommendation

Hi GMs - I currently play 5e and have only the Monster Manual. I'm looking to get a bestiary module but have limited budget. If I was to get only one of these modules, which one would you recommend? My main criteria would be easy-to-run, balanced monsters. Creature Codex Tome of Beasts Tome of Beasts 2 Tome of Beasts 3 Mordenkainen Presents: Monsters of the Multiverse Also keen to hear any other bestiary recommendations. Thank you for your thoughts!

My game is also D&D 5E and I was using only the Monster Manual until last May, when I purchased Mordekainen's. I picked up Tome of Beasts 2 for free through my Pro subscription last November. I found Mordekainen's to be mostly an update for existing stat blocks with little new content. Tome of Beasts 2 is much more interesting; it gives me opportunities to expose my players to creatures they've never seen before. (Most of our group have playing various versions of D&D since the 1980's or earlier.) I'll likely be buying stuff from Kobold Press in the future.

Tome of Beasts 1 & 2 are both great, not sure about 3 as I don't own that yet myself but all the Kobold Press monster manuals I've seen so far are decent. Creature Codex is a little older but still okay. I would recommend Tome of Beasts 1 or 2 over those though. Kobold Press include a lot of fey-type monsters, which can be really cool if you want to run a fey-themed campaign. As Rick said above, Mordenkainen's adds nothing in terms of monsters and really is a waste of money if you already own the 5E Monster Manual. 

Thanks all - looks like consensus is for one of the three Tome of Beasts. Still not sure which one to get - obviously getting all of them would be good but can't justify the cost.

All Kobold Press bestiaries are excellent. If price and total cost is a concern and you have a pro account you have the option to transmogrify monsters/npcs/maps/handouts from adventures. In this way for the same price you can get monsters and an adventure. Since i am a nerd here is a list of adventures (i bought) with more than 100 npc's: name nr of characters Empire of the Ghouls Module 364 Tomb of Annihilation 292 Tales of the Old Margreve Adventure 224 Explorer's Guide to Wildemount - Adventure Module and Gazetteer 205 Tyranny of Dragons Module 196 Curse of Strahd 192 Journeys Through the Radiant Citadel 184 The Wild Beyond the Witchlight Module 183 Scarlet Citadel 166 The Potbellied Kobold 162 Critical Role: Call of the Netherdeep 143 Dead in Thay (Tales from the Yawning Portal) 132 Courts of the Shadow Fey 125 Hoard of the Dragon Queen 116 The Rise of Tiamat 115 Dragonlance Shadow of the Dragon Queen Module 113 Humblewood Adventure 101