Usually normal. Either because that's the default option and I don't feel like changing it, or because that provides the most balanced gameplay.
There's exceptions though, if a game's good enough for a re-play I'll likely choose the harder setting. Doesn't happen a lot, because most games I play though a second time don't even have difficulty settings (most Nintendo games or simulation games like SimCity). Also, I set certain RTS games like the Total War games to a harder difficulty because that improves the AI which makes the game more interesting and more realistic. Lastly, I only play(ed) Guitar Hero in Expert mode because that was the only way the games were fun.







