Yes it's true that you see Stadshuset from many places in the city. Mostly only a small part of it. It might not be the most beautiful building ever, but it became one of the most famous sights in the swedish capital city. If you want a really nice view of Stadshuset, go to Riddarholmen. More precisley: Evert Taubes terrass. It's not exactly a secret spot, as especially in summer, there are many touristcars there. Mostly the "hop-off, take a picture, hop-on"-thing (which is nice, when you want to see the most important spots in a city of course). But it is worth to spend some more time there. And especially to walk from Gamla Stan to Evert Taubes terrass. You pass by Riddarkyrkan (the church) and some nice colourful houses. From Evert Taubes terrass, you have a beautiful view over the water. Södermalm to your left and of course Stadshuset to your right. So you will not only see the tower but also the rest of the building. It is particularely nice before sunset when the light on the building is perfect (photographers will know what I mean).
Check out the blog to find more information about Stockholm and what to do and see there. There are different categories (click on the word) such as Gamla stan, Djurgården, Östermalm, food and drinks, free things, museums, sights and photospots, what to do on rainy days and much more!