Dungeons and Dragons is a game of endless possibilities and decisions. All your decisions are limited by two things, your creativity and your characters skill set. There are a ton of different combinations and options in the Player's Handbook. Whether you’re an experienced player looking for something new or you’re a new player trying to bring your ideas to reality. These character creation accessories and books give you additional races, sub-races, classes, and class archetypes.
A quick honorable mention for top character creation accessories is the Guildmaster’s Guide to Ravnica. There are two reasons it doesn't make this list is mainly due to the fact that it is based on Magic the Gathering. This makes the product more niche and unlike Critical role Magic isn't synonymous with the Identity of Dungeons and Dragons. As well as it only adds character races, which is great, but limited compared to the others on this list. Not to say this product isn’t amazing, it really is. It adds a ton of political parties, a whole new universe, and some great character races.
5 Explorers Guide to Wildemount
Coming in at Number five is the newest of the entries, Explorer's guide to Wildemount. From the world of Critical Role now to your table, coming in this book are some great entries on the classes. From the three sub-classes that totally crank up that out of this world aesthetics. Not only flavor but also in utility aspects of play. The only thing keeping this entry as low is the same reason that Guildmaster’s Guide to Ravnica was an honorable mention. It isn’t completely canon, and it is a niche to critical role.
4 Sword Coast Adventurer's Guide
Following in at number four is the Sword Coast Adventurer’s Guide, this book gives you more classes, and many more backgrounds. You even get more spells! I haven’t even gotten to the best part. It goes in depth on all the classes and adding a lot of flavor and certain examples to help you flesh out your character. This is a great resource in adding a lot of substance to your character and reasoning to why you may be adventuring.
3 Wayfinders Guide to Eberron
At number three we have Robots and Shapeshifters! I’m only slightly kidding, this book does provide changelings who are shape shifting like beings. Also Warforged who are the culmination of mechanical knowledge and the presence of the arcane surging through them. This book also comes with a new class, as well as the Dragon Mark races! All of these also come with magical weapons and much more! This book provides a lot of substance so you can easily differ your character from any other on the sword coast.
2 Volo’s Guide to Monsters
Coming from the adventurers journal entries, enters number two with Volo and his guide to monsters. In this book you will find races from celestial related beings and half giants all the way to goblins, bugbears and ogres (oh, my). From the allotment of races to the extreme background for many monsters, yuan ti, in particular. You can make a character like lizard folks with their quirks and the Aasimar with their angelic guides. Each allowing many role play shenanigans and interesting interactions. Although it is only races this book gives you so much information and customization that every character will be special even if it is the same race and class.
1 Xanathars Guide to Everything
When a book says guide to everything you have to put it at number one... right? Well that’s what i had to do, within this book you’ll find many new sub-classes. All of these sub-classes allow you to take your customization to the next level. Not only that but you gain access to a ton of new spells! You gain things to do during your downtime, and you gain more tools to use for your character. This book is the best way to expand on your character in more ways than just the initial character creation. It is a book that will continue to allow you to grow with your character.
Conclusion on Top Character Creation Accessories
Any of these books are a great decision on expanding on your character creation accessories collection. They all have a lot to offer outside of just character creation. I believe overall the best for character creation would be Xanathar's due to the fact it expands the most on classes. Volo's has the best choice for character races and fleshing them out, while Sword Coast gives you lore and more backstories to flesh out your pre-adventuring days.