This is a very fine number of Lovecraft's stories though in this collection his longer works predominate over the shorter stories.
Amongst others, this volume contains three of Lovecraft's most iconic stories, The Horror of Dunwich, The Thing in the Doorstep and The Case of Charles Dexter Ward.
At the Mountains of Madness is another long story that starts phantastically well, though it withers a bit towards the end.
The short stories are not Lovecraft's best, but The Music of Erich Zann and The Temple hold their own fairly well.
Most notably, the near complete absence of his oniric tales (I can't think of anybody who would rank those as their favourites) makes this volume his most palatable.
The comments and edition by S.T. Joshi is second to none and his notes at the back are a great help to contextualise both in time and within Lovecraft's opus each of the tales.
Just for The Horror of Dunwich, this collection is worth every penny. As a whole, it's brilliant.