Here’s a concise, curated list of highly regarded guided‑tour companies, grouped by the kinds of trips they do best and with a short note on why people pick them. I’ve included trusted sources where these operators have been recognized.

Luxury / private‑custom

• Artisans of Leisure — Top-rated luxury private tours and highly personalized itineraries (Travel + Leisure World’s Best #1 tour operator 2025). (artisansofleisure.com)
• Abercrombie & Kent — Longstanding leader in luxury safaris, tailor‑made travel and expedition cruising; many industry awards for luxury service. (abercrombiekent.com)

Small‑group / value + local guides

• Intrepid Travel — Market leader for small‑group, locally led adventure travel with eco/responsible focus and many short/affordable departures. (en.wikipedia.org)
• G Adventures — Large independent small‑group operator known for budget to midrange adventure trips and community‑based tourism (frequently recommended alongside Intrepid). (cntraveller.com)

Expeditions, wildlife & experiential learning

• National Geographic Expeditions — Expert‑led, science‑ and conservation‑oriented journeys (strong for wildlife, photography, polar and cultural expeditions). (nationalgeographic.com)
• Overseas Adventure Travel (O.A.T.) — Known for small‑group expedition cruising and remote/expedition itineraries (recognized in recent Readers’ Choice awards). (prnewswire.com)

Ecotourism / conservation‑focused

• Wilderness Travel — High‑quality small group adventure and active trips with deep destination expertise (often recommended in industry roundups). (cntraveller.com)
• Gondwana Ecotours — U.S. operator focused on small‑group ecotourism and sustainability (wildlife & community engagement emphasis). (en.wikipedia.org)

Specialty / high‑end adventure & bespoke

• Abercrombie & Kent (also in luxury above) — also excellent for safaris and luxury expedition cruises. (abercrombiekent.com)
• Black Tomato / Scott Dunn — boutique bespoke operators for ultra‑custom, luxury adventure and unique access experiences (frequently listed among top specialists). (cntraveller.com)

How to pick among them (quick tips)

• Trip style: choose luxury/private (Artisans of Leisure, Scott Dunn) vs small‑group/adventure (Intrepid, G Adventures) vs expedition/wildlife (National Geographic, O.A.T.). (artisansofleisure.com)
• Group size: small (average ~10–16) for more interaction, private tours for full customization. (en.wikipedia.org)
• Responsibility: look for companies with clear sustainability/community policies if that matters to you (many leaders publish sustainability pages). (en.wikipedia.org)
• Reviews & awards: check recent industry awards and reader’s‑choice lists (Travel + Leisure, Condé Nast Traveller, National Geographic) to confirm current reputation. (artisansofleisure.com)

If you want, I can:

• Narrow this to a specific destination (e.g., Italy, Galápagos, East Africa, Alaska) and recommend the top 2–3 operators for that place; or
• Compare two companies you’re deciding between (price, group size, itinerary style, sustainability); or
• Pull recent reader reviews/prices for a specific itinerary and travel month.

Which would you like next?