Last year we went to Wengen Switzerland and this year Sils Maria south of St. Moritz. Loved both, but Sils was even more beautiful. Smaller, much less crowded, with a lake surrounded by mountains and meadows covered with wildflowers. Located at about 3000 ft. We love to find a similar situation in the Tirol.
Have a look above Seefeld in Tirol.
Take a look around Otzal in Tyrol.
I like the southern side of the Grossglockner High Alpine Highway (going south of Zell-am-see). The area north of Lienz, Austria is where I'm talking aobut.
Seefeld in Tirol is the hiking area, offering 200+ hiking trails with a total length of 400 miles (650 km).
As far as lakes go, the Achensee area in Tyrol is a very beautiful and popular choice but I think it tends to get crowded at times. (https://www.achensee.com/). There's a lot of artificial lakes in Tyrol, tucked away in the valleys.
Both of these are accessible from Mayrhofen in the Zillertal valley.
Something to consider for wildflowers... I like a bit farther south in Südtirol in Italy in June - July. The Pustertal Drei Zinnen area and the top is the Seiser Alm with Schlern the largest alpine pasture in Europe. High tourist season starts about mid June. Trollblume are one of my favorites.
thanks to all for your great suggestions