For my money, Barry Eisler's books about half-American/half-Japanese assassin John Rain are some best thrillers since the glory days of Ian Fleming and Adam Hall. I can't help but be enthralled by the adventures of this jazz-loving, Scotch-drinking, neck-breaking killer.
Like Fleming before him, Eisler doesn't shy away from mentioning name-brands in his novels. Some critics deride this sort of thing as gimmicky. I disagree. I think it just roots the series in the real world, and gives me a better connection to the character. I'd prefer to know that Rain drinks Laphroaig and listens to Bill Evans than merely be told he drinks single-malts and listens to jazz.
In the third book of the series, Rain Storm, we learn what type of watch John Rain normally wears: a Traser P5900. As something of a watch enthusiast, this was a key revelation. It was also not an arbitrary decision on Barry Eisler's part. In the book's acknowledgements, he specifically thanks a bunch of real-life operators for inspiring him to issue Rain a Traser wristwatch.
The P5900 is an interesting choice of watch for an international assassin or would-be international man of intrigue. It's black, lightweight, and rather nondescript. The bright lume means it should be readable even in the darkest environments. And it isn't too expensive, so one wouldn't shed tears if it was lost or damaged during a mission. Really, it rather strikes me as the Glock of analog watches.
Would I ever buy one? That's a tough question. It's a nice watch for all the reasons I mentioned above, thought a bit smaller than I'm used to. Also, I am a bit of an automatic purist, and the P5900 is a quartz watch. For the money, I would be tempted to just get an Seiko 5 auto, which are probably the best budget watches on the planet. Still, I don't deny being tempted by the Traser. It would feed into my John Rain fantasies, and whenever I checked the time I would no doubt be tempted to sip some Laphroaig, listen to a bit of Bill Evans, and go practice Jiu-Jitsu.