I think part of why Skyrim worked was that 1, there was a lot to find, and 2, there was a sense of reward - hearing that little sound effect when you found a new area, watching you map gradually feel it - that kind of felt like an xp bar in it's own sense.
Fallout 3/New Vegas (obviously) were similar, but in ways did things both better and worse: On the one hand, getting xp for exploring was a definite advantage to do so, and considering scavenging was a major part of the game, was good for getting caps. There was also the thrill of almost 'going down the rabbit hole' - you could enter a building thinking you'll clear it in 5 minutes, then end up there for 20, killing new enemies, exploring the fluff, or maybe even tracking down a unique weapon. However, in general, Skyrim had MUCH better locations - some of fallouts were definitely a bit bland/uninspiring.
Fallout 3/New Vegas (obviously) were similar, but in ways did things both better and worse: On the one hand, getting xp for exploring was a definite advantage to do so, and considering scavenging was a major part of the game, was good for getting caps. There was also the thrill of almost 'going down the rabbit hole' - you could enter a building thinking you'll clear it in 5 minutes, then end up there for 20, killing new enemies, exploring the fluff, or maybe even tracking down a unique weapon. However, in general, Skyrim had MUCH better locations - some of fallouts were definitely a bit bland/uninspiring.