It's also Anvil for me, especially if I play a mage. Thus I can have a separate chamber for my experiments, enough storage room for supplies, staffs, etc. and a great view from the balcony.
It's also sufficiently cheap to buy it early on. I only go with other houses if it suits my roleplaying. That being Waterfront or Bravil for a shady character and Bruma for a Nord.

I can′t tell you what house is best for you. But for me it′s the house in Bruma, where I feel at home

I find the Bruma house rather cosy and plenty room for decorating unless you're a total decorating junkie that has to display every piece of equipment. Otherwise the anvil house is probably best for cost/size and has lots of room.

I usually end up with the character owning all of them (and a few mod-added homes as well) but I find that the one I use most is the IC shack, because of its central location. I don't tend to save things for later, or make collections, so storage ins't an issue. A player home is just a convenient bed, and somewhere to spar with a summons to raise a stat from time to time. The IC shack has that, and it's on the way to anywhere else. Sometimes I don't bother adding the optional furnishing to it, but it still gets the most use.

I almost never buy the Leyawiin one, as the White Stallion Lodge is better (especially with Mazoga in residence), but all the rest are just as good as each other, and a good way to use up the gold.

The best thing about the Imperial City Shack is that it's central to the game, esp. if you don't use Fast Travel. Otherwise, yeah, the Anvil house is best and the quest is fun.

I personally Love Frostcrag spire, but as I'm not a mage I use Battlehorn castle. In Vanilla, I'd recommend picking the town you visit often or simply like, and buying the house there.

Benirus Manor in Anvil is cheap and has the most containers. While Rosethorn Hall in Skingrad is more fancy with display cases but is more expensive.