Short answer — in 2025 the safest “best” online casinos for U.S. players are the large, state‑licensed operators (availability depends on the state you’re physically in). The consistent top picks are:

1. BetMGM Casino — strong game library (slots, live dealer, table games), big welcome offers and integrated MGM Rewards; live in the major regulated iCasino states (Michigan, New Jersey, Pennsylvania, West Virginia). (casino.BetMGM.com)

2. FanDuel Casino — well‑regulated, polished app, exclusive branded games in markets where iCasino is allowed; live in CT, MI, NJ, PA and WV (geolocation required). (FanDuel.com)

3. DraftKings Casino — full casino tied to the DraftKings ecosystem (sportsbook + DFS + casino in supported states); available in regulated iCasino states such as CT, MI, NJ, PA and WV. (casino.DraftKings.com)

4. Caesars Casino — big catalog and loyalty perks for Caesars customers; licensed and operating in regulated casino states (MI, NJ, PA, WV). (SportingPost.com)

5. Regional/state operators & newcomers — in some states other licensed brands (e.g., local racinos/resort operators or state lottery partnerships) also rank highly; availability and promos vary by state. (See each operator’s “where we’re live” page before signing up.) (casino.DraftKings.com)

Notes, risks and alternatives

• State rules matter: online casino (iCasino) legalization is handled state‑by‑state. Even top U.S. brands only offer real‑money casino play where the state regulator has licensed them; you must be physically located in that state to play. Always check the operator’s state list before depositing. (casino.BetMGM.com)
• Sweepstakes / social casinos: if you live in a state without regulated iCasino options, sweepstakes-style platforms (Chumba, LuckyLand/Pulsz, etc.) let U.S. players play for prizes without a real‑money casino license — but the business model and prize rules differ from regulated casinos; research redeem rules and reviews. (TalkSport.com)
• Offshore/crypto casinos: many popular 2025 “best lists” include crypto/offshore sites (Jackbit, Bitstarz, ThunderPick, etc.). they often offer fast crypto payouts and large game libraries, but they are not licensed by U.S. state regulators and carry higher legal, payment‑processing and consumer‑protection risk. If you consider them, understand the legal and withdrawal risks first. (AccessNewsWire.com)
• Age & responsible play: you must be 21+ (state rules vary) and follow geolocation and ID/KYC checks on licensed sites. Use deposit limits and self‑exclusion tools if needed. State regulators advise using only licensed operators for consumer protection. (CTInsider.com)

If you want, I can:

• Check exactly which of these operators are legal in your specific state (I’ll need the state), or
• Compare sign‑up bonuses, withdrawal methods and average payout times for 3–4 sites you care about.

Which would you like?