A wonderful and expansive anthology of German poetry (from early Mediaeval beginnings to in this particular edition around 1998, although the first edition was actually published in 1836, thus only about six years after the death of Johann Wolfgang von Goethe, and since Theodor Echtermeyer was, in fact, the original compiler, he is of course, also long deceased), and yes, I do very much consider Deutsche Gedichte: Von den Anfängen bis zur Gegenwart amongst my personal favourites (not perhaps a book to read from cover to cover, but I often browse through it, savouring and relishing favourites of German lyricism).
An older edition (from the early 80s and unfortunately somehow missing in action from my bookshelves) was required as a textbook for a number of my undergraduate university German literature courses, and while Deutsche Gedichte: Von den Anfängen bis zur Gegenwart does and would NOT, of course, present ALL poems by EVERY German poet, the selection is in fact and indeed amazingly complete and detailed; and in my opinion, all of the important, most famous German poets and their best known, most essential, most readable pieces are, indeed, usually and generally included. Most highly recommended, and while there are many editions available, I would definitely and strongly suggest the most recent edition of Deutsche Gedichte: Von den Anfängen bis zur Gegenwart, as it will by necessity and nature also include the most recent poets and their verses (but that all being said, please do note that the presented poems are all in German, and as Deutsche Gedichte: Von den Anfängen bis zur Gegenwart is not a dual language offering, but a monolingual tome, a good and decent level of fluency in the German language is strongly suggested, and for many of the longer and more expansive offerings, even required).
And finally, if you are actually considering earlier (or even the earliest) editions of Deutsche Gedichte: Von den Anfängen bis zur Gegenwart, aside from these editions obviously not containing the most modern and recent poets, please note that the print, the script would (at least until the 1950s or so) likely be presented in "Fraktur" (or what I tend to call German Gothic script), which takes some getting used to, and is not always that easy to read.