Perhaps not the most impressive ascent in terms of sheer numbers, but onsighting the 1220m/39 pitches Il Pesce a.k.a. The Fish on The Marmolada in the Italian Dolomites is always impressive.
Since its first ascent, from Koller and Sustr in 1981 it has remained a route which even the top climbers have the utmost respect for.
I suggest you read the Pou brothers' account to find out more.
Right now, they are waiting for better weather in the Aosta valley on the Italian side of Mont Blanc/Monte Bianco, where they are/were planning on opening a new route.
Source: Hermanos Pou