I would agree wholeheartedly about the Daily Mail puzzles, which have well-constructed clues and offer a very consistent standard of difficulty. After going through a 'difficult patch', Everyman has a single setter once more and seems to be getting back to its old level, so also worth trying (if you're looking at ones from the online archive, go for number 3,771 or before). Personally I would not recommend the Guardian daily crosswords for a relative newcomer as the use of a large pool of setters means that the quality and difficulty of the puzzles vary dramatically.