Things I care about:

always prefix this pointer when accessing member variables or methods of a class
use Allman-style bracing and indentation
also brace single line statements
use camelcase for identifiers

Things that are nice to have:

have a free line when a "thought" of a code snipet got done
UpperCamelCase for class identifiers, methods, const variables and non-autogenerated files
else: lowerCamelCase