Williams manufactured a nice line of electric toy trains, most of them being updated reproductions of Lionel models. They included can-motors rather than the open-frame motors of Lionel's post-war period, so they were extremely reliable and smooth running, at least in my experience. The primary complaint was (1) weak smoke-units made by Seuthe, and (2) the generic sound board (True-Blast) was not the best. They were relatively inexpensive.
A few years ago Bachmann acquired the line from Williams and made a few changes. They've upgraded the sound, introduced a few new models and paint schemes...they've also upgraded the price. I haven't purchased any of the Williams-by-Bachmann trains (yet), so I can't opine on this new generation.
Here's a Williams GP-38 I acquired second-hand at a meet a number of years ago:
Extremely powerful with its dual motors, I don't have enough freight cars on the shelf to slow this thing down. If I ever get around to trying my hand at weathering a piece, this might be the one.