D&D 5E Book (printed) Recommendations?

[Matrix Sorcica]

Both Monster Manual Expanded I and II are really great and will be in print within a few weeks. Hundreds and hundreds of variations on MM, VGtM and ToF monsters.

 

[R_J_K75]

The Creature Codex by Kobold Press is great. I love the fact that the players are not familiar with them. Puts the tension back into the game, as in no meta-gaming:

Creature Codex for 5th Edition - Kobold Press Store

A Rampage of New 5th Edition Monsters! DM: “A mysterious figure in a cloak approaches you in the tavern…” PALADIN: “Aha! This must be a wizard with a map to a dungeon!” DM: “…and he’s ticking.” ROGUE: “RUN!” Whether you need scuttling dungeon denizens, alien horrors, or sentient avatars of the...

koboldpress.com

Yep. I own it and use it often. Good quality and value.

 

[Ralif Redhammer]

Kobold Press' monster books are top notch, absolutely. I'd also recommend Cawood Publishing's Monsters of the Underworld, while we're talking monsters. The art is done by the same person that does the Life of the Party comics, which gives it a distinctly different feel.

Nord Games Remarkable Inns & Their Drinks is more system-neutral, but I'm always a sucker for fantasy tavern supplements.

Finally, I find myself often in need of new magic items that the players haven't seen before. Paradigm Concept's Arcanis: Forged in Magic Reforged fills that niche nicely. There are some really cool magic items in it. My only caveat is that some of them are tied to their particular setting, and uncoupling some of that isn't always easy.

 

[Fenris447]

I'll add to the chorus praising Tome of Beasts and Creature Codex from Kobold Press. Excellent monsters all around. My dungeons aren't complete without a least one creature from these books.

I'm also a fan of Ultimate Bestiary: Revenge of the Horde by Nord Games. If you have any desire for more kinds of kobolds, gnolls, orcs, or goblinoids that can still fit in perfectly with what exists, this is what you need. I did a whole gnoll invasion arc and used these to great effect.

The last one I'll recommend is Monte Cook Games' Arcana of the Ancients. It pushes their setting's theming a little heavily for my tastes, but the crunch of magitech items and interesting monsters can be put into any game that includes science fantasy stuff.

 

[Shiroiken]

While not necessarily supplements, the 5E settings of Thule and Midgard are really good. Even if you don't use the settings, they're littered with ideas that can be adapted to your campaign. Several of the player options are really interesting as well.