My current one is from Issentiel and is my favourite, a fairly slim design with a pull tab and comes in a range of colours. My red one has held up pretty well, almost two years old now and has been used almost every day.
I've also always liked the look of Lucrin cases, but never owned one so can't really speak for the quality.
I had a Beyzacase leather pouch for my iPhone 5 and remember that being quite good, along with a Proporta sleeve, but not sure if the latter is a 'luxury' sleeve.