"The Sword and the Flame" (TSATF for short) is probably the single most popular set of colonial era rules. I definately enjoy playing those rules. They are very easilly adapted for different periods, and there are many variants available. A friend of mine has been playing TSATF for about 30 years, and he has used 20 man units, 10 man units, and 5 man units. There are variants using d10 and d20 for firing, with the d20 allowing finer grades of difference between firing units' rifles and training.
One of the best places to look for info on TSATF, with game reports, is the place where Larry Brom developed the game, in Jackson, Mississippi, with the Jackson Gamers:
http://www.angelfire.com/games3/jacksongamer/There's a colonial section there, and a section specifically on TSATF. The guys in that club have been playing TSATF since before it was published.
Another spot for some interesting TSATF game reports is
www.warflag.com for a French Foreign Legion variant. Just click on the link to "The Red Shadow" to see pics and reports.