Peril glasses? Really? All the cool toys from the imagination of Adams and you pick the lame peril glasses? What about the infinite improbability drive? Or the SEP cloak? Or maybe one of the various devices designed to distract you so that you miss when you throw yourself at the ground? Or, heck, even the guide itself (an e-book reader that can tell you anything about anything and is able to puzzle out what you're looking for from a simple question)?
In Star Trek the replicator is what I'd want to have. 99% of the time they only use it as a glorified microwave, but they show that the things can make pretty much anything. Consider that for a moment. Want an iPad? It's yours as quick as you can say "Computer, iPad". Heck even as just a food dispenser it's freaking awesome, in no small part because it also disposes of the dishes afterward.
Oh, and holodecks would realistically be no more addictive than World of Warc....eh... nevermind.
Some other gadgets to consider:
The sarcophagus from the Stargate shows
Zatnitticas, also of Stargate origin
A tasp from Ringworld
The laser suck-you-into-the-computer thing from Tron
I'll stop now....I could go all day listing the gadgets I'd like to have from sci-fi.