LOS ANGELES (Zap2it.com) - Only eight dramas have finished a season as the No. 1 show (in terms of household ratings) on television and the occupations represented on those dramas have been fairly restrictive. As the years have passed, doctors, cowboys, more doctors, more cowboys, oil barons, still more cowboys and more oil barons have claimed the top spot. As remarkable as it seems, no legal drama has ever topped the charts, nor has any show about a personal valet to President Lincoln.

All hail "CSI: Crime Scene Investigation," then, for venturing into uncharted waters this season. The CBS series finished the year in the top slot, averaging a 16.1 rating/24 share. "CSI" was watched by nearly 26 million viewers per week and dethroned recent champs like "Friends" and "ER."

"CSI" is only the third CBS drama to finish the year ahead of the pack, joining the ranks of "Gunsmoke" (four years on top) and "Dallas" (three annual victories). It also becomes the first crime drama to lead the ratings.

For those scoring at home, "Bonanza," "Dynasty," "Wagon Train" and "Marcus Welby, M.D." are the other dramas to win a year.