Here are top fast-casual chains in the U.S. that stand out for burger variety (different patties, creative signature builds, toppings/customization, and frequent limited‑time creations). Short note on what each does best and a source.

• Shake Shack — Known for a rotating roster of creative specialty burgers (e.g., truffle, seasonal mashups), plus beef, veggie and ’shroom options and regular limited‑time releases. Great if you want craft-style, chef-driven varieties. (shakeshack.ca)

• Five Guys — Extremely customizable build‑your‑own model (hundreds of topping combinations) with generous portions and simple, fresh ingredients — ideal if you want to tweak every detail of the burger. (fiveguysmenu.com)

• Smashburger — Focuses on “smashed” patties and a menu of signature gourmet burgers (plus frequent new items), offering different styles and spicy/cheesy variations. Good for crispy-edged, flavor-forward patties. (Smashburger.com)

• Hopdoddy Burger Bar — Crafts inventive, chef‑driven burgers (wagyu, bison, seafood and several unique topping combinations), plus alternative proteins and bun/“bowl” swaps. Excellent for adventurous toppings and premium patty options. (hopdoddy.com)

• BurgerFi — Broad burger lineup (double patties, specialty sandwiches, plant‑based VegeFi) and frequent new items — a good middle ground for variety including more indulgent and plant options. (BurgerFi.com)

• The Habit (Habit Burger Grill) — Frequently ranks highly in burger polls and offers variety across chargrilled beef, chicken sandwiches and seasonal items; known for good quality and specialty builds. (sfgate.com)

Notes:

• Menus and limited‑time offerings vary by location and change often; the chains above are known for either large customization options or regularly rotating signature burgers. If you want, I can give the best options near you (city or ZIP) or recommend which chain to choose for a specific taste profile (e.g., wagyu/bison, plant‑based, spicy, gourmet toppings).