The most challenging aspect is actually finding something worth playing.
+1 on that.
As compared to games from 10, 12 even 15 years ago, it seems that developers today are more concerned about producing crap, as compared to producing a quality product.
I can count one 1 hand, maybe 2 hands how many games I would consider great - Doom, Quake multiplayer (quakeworld), Diablo 1, Half-Life, Warcraft II: Tides of Darkness, C&C Gold edition, Diablo II, Team Fortress Classic, left 4 dead 1 & 2,,,,,.
It seems to me that the majority of great games were made before 2004, with most of the truly "great" ones being made before the year 2000.
Besides Left 4 Dead 1 and 2, I have not had a game really grab me since half-life 2.