GASLIGHT is the only set rules I have used for VSF games and would probably work well for Pulp too (see below for details of the Pulp supplement). Although some parts of the rules seem to play strangely, the rules work very well on the whole. I find them easy to use and very adaptable to any size of game or genre. They are also fun to play. As result, I have stuck with these rules and and haven't needed to look for another set.
The rules aim for cinematic effect rather than strict historical accuracy. Unit leaders and individual 'Main Characters' have their attributes rolled, while normal troops ('Extras') are mainly there to die gloriously and make the MCs look good!
For VSF games there are good rules regarding steam-tech vehicles, including some nice damage effects.
The rules are also well supported by a very active Yahoo group moderated by the guys who wrote the rules:
http://groups.yahoo.com/group/GASLIGHTrules/The rules are cheap to buy and stocked by several companies (try Old Glory UK, or Brigade Games in the US). In addition to the main set there are several supplements:
G.A.S.L.I.G.H.T. - the main rules set
The Journals of Victoria Hawkes (The American Civil War by G.A.S.L.I.G.H.T.) - supplement containing several game secenarios with full unit lists and and special rules for steam-tech vehicles and weapons introduced in the scenarios. Very useful supplement, giving good examples of how the writers intended games to be set up.
Battles by G.A.S.L.I.G.H.T. - supplement with alternative rules to enable big battles to be played. Also contains rules for huge vehicles (leviathans). Even if you don't play with the big batlte rules, these contain some useful additions to the basic rules. Having played my first huge Battles game just before Christmas I have to say that these rules worked perfectly giving us a great game.
To be Continued....by G.A.S.L.I.G.H.T. - rules for using G.A.S.L.I.G.H.T. for pulp-type small scale skirmish games in linked campaign comprising a number of 'episodes'. I haven't played these yet, but having looked at them I think that will be my preferred rules for pulp and small character-driven VSF games.
Adventures and Expeditions by G.A.S.L.I.G.H.T. - these contain alternative rules for role-playing in the G.A.S.L.I.G.H.T. world. Personally I think that these stray too far from the main rule set. My preferance would be to use the To be Continued.... rules and maybe just use this set for its ideas on character and scenario generation.
Hope this helps.
