The industrial age is the only age where my research pattern is (almost) set in stone.
Background: I play on emperor, and have normally got a small tech lead when I enter the industrial age.
My research pattern is as follows:
1) steam power: Get railroads ASAP. It increases growth/production enormously.
2) Industrialization: A divercion from where I want to get fast, but worth it for the factories and partly for the wonder(s)
3) Electricity: On my road to the ToE wonder
4) Scientific Evolution: If everything goes as planned, I will have a city working on a palace, ready to switch to ToE and finish it in a turn or two. If so I set my research rate to 0% and goes for
a5) Atomic Theory and
a6) Electronics: Those two are the most expensive techs (giving you most from ToE), and will give you access to the Hoover Dam and a production rate that outproduces the remaining civs together.
If the ToE will take 4 or more turns to build, I will research one interim tech while waiting for it to be finished. I then go for:
b5) The Coorporation: A cheap tech that can easily be researched in excactly as many turns as I need for building ToE.
or
c5) Replacement parts: An important tech that secures your borders for the rest of the game. With lots of artillery and infantry, noone will be able to conquer you. Replacement parts is much more useful than coorporation, but if I cannot finish it as soon as I build the ToE, then I will choose the coorporation instead.
In case of b5 or c5, when I get ToE, atomic theory and electronics will always be the two I get myself from ToE.
Then after Electonics, I will research Replacement parts first, then followed by coorporation (unless I have one of these already, of course), then refining (to find out whether I have oil, or if I need to conquer it), followed by the shortest route to motorized transport. Then flight and radio, and a new age has begun
Nationalism I here you ask, what about nationalism? Well, unless I'm in a war where I sorely need riflemen, then I won't bother. I rather buy (or preferrably, steal) it later on when all the other civs have it. The same goes for communisn and espionage. I then pick out a civ that has it but lacks a few techs that the other civs already have, and get a trade that cost me nothing.