Rome in the west fell. Rome in the east (Byzantium) persisted for a long time after.
The dark ages generally refer to the West, so I stuck to that. In areas aside from Western Rome, life pretty much went on as normal until civilization went away.
While the economic achievements of medieval society, as jfruser pointed out, were limited, art, literature, and even certain types of technology continued to grow and improve.
With very little strides here and there. And mostly in places that were not hit as hard by the fall of Rome.
In this case, I give you Petrarch and Dante in literature and Da Vinci and Giotto in arts. I give you gothic architecture.
Again, a little here, a little there. And these are not at the hight of what were some seriously dark times.
The insulae STANK, literally. People would get sick and die from just living in them, and the ones outside Rome were worse.
Sure they did. You think sharing a hut with pigs or other live stock smelled any better? Fact, ancient cities stunk.
And of course, they had brigands too, especially during the late Republic.
Uhm...no. The late republic was a good time to live within the boundaries of Rome. Rome wasn't sacked or seriously harassed herself for literally hundreds of years. Much else within the empire was pretty damn stable as well with the exception of the occasional civil war here and there. In which case, still Romans, so not to terribly bad. With little exception, outside of the late empire, living within Romes boarders was pretty safe provided you weren't ride on the boarder or something.
Precisely. In Rome. Do you think the average Imperial subject living in, say, Spain, could do it if he didn't live in a major center of the Empire
Even just an average size city had amenities that shined compared to the dark ages. Public baths, advanced hospitals (these guys were doing eye and brain surgery 2000 years ago, they had a basic understanding of infection), markets, everything you could want or need. Not everyone lived in them, but most lived within range of them. Especially if you were in an area that was in Roman hands for a good time.
You are confusing myth with reality here. A lot of these 'huts' had pretty good ventilation and the peasants bathed (in rivers, mind you, not actual baths).
People rarely bathed, they had no understanding of it's benefits aside from not stinking. And unless you lived in the middle of nowhere you didn't want to drink the water let alone bathe in it. Even Elizabeth (little later mind you, but still) bragged about bathing once a month. ONCE A MONTH, Romans living in a city would nearly vomit at the thought.