I use the travel style low-rent ones. I've been importing videogame systems from japan and the u.s since the early 90s and have always used them as our voltage is 240v here. I've run these for years on (when released) high-end electronics and am still using one I bought 10 years ago on my u.s Wii. Theres only one I ever had a problem with, in that it would overheat and cut out with my japanese Dreamcast in 1998, but the same priced replacement I got has worked perfectly since, to this very day.
I've never bothered with expensive ones as the cheaper ones have worked perfectly for me over thousands of hours of service. I'm not sure if this is the same with step-up convertors or not though, so please forgive me if this information turns out to be useless.
