Almost all spot index options in the US are european style, unless you have a special preference towards options on futures.
Thanks Preference for futures options is because very low margin requirement . I donot know if things have changed for index options as reg t is out. Please advise. Much appreciated.
If you qualify for portfolio margining then this shouldn't be a problem, otherwise reg t still applies.
There are Euro-style currency options traded at CME. I've traded European style EuroFx options frequently. I'm not aware of any others (Euro-style futures options) with significant liquidity.
Bring up the option table for EUR (the futures contract at GLOBEX) and use the filter to just look at the "XT" Trading Class. Those are European style.