Folowing features are marked as most useful:

** Strings in switch

** try-with-resources statement

** Multi-catch
this is allowed:

catch (NullPointerExcelption | SqlException exc1)

** Underscores in numeric literals

10_000 is equal to 10000

** Improved type inference for generic instance creation
this is allowed:

Map<String, List<String>> retVal = new HashMap<>();

More info available here.