What's the best way to increase the horsepower in my Honda Civic?

you could put a turbo on it, but that will cost you in the $5000 range, for a 75-100HP gain... and if its not a stick shift thats not even worth it because it will take no time to kill that auto tranny. Also that puts some undue strain on the motor as well. dont nitrous it unless you are willing to build the motor up a bit as that causes more stresses than any other and its only a temporary boost of power. There are many things that can be done to the engine internals i.e. the chip you are talking about for a bit of a gain in power too. Dont fall for the cheapo "performance" chips on ebay though because they dont do anything.

That is a tough question to answer given we dont know what kind of power you are looking for and what kind of driving you want to use the power for.

you can get and engine swap say a b18c or an h22 or k20 and if not then you can keep the stock engine and get simple bolt-ons like intake headers and exhaust.. if that doesnt get what you want you can take off power steering and a/c to gain more power as well and maybe with some more money you can get cams and cam gears all this will gain you power but if you wanna turbo then i would suggest you get a re-sleeving for yurr engine block so that it can withstand the stress that the turbo dishes out ... hope that helps

An engine swap. The stock engine is a junky D series block.

You swap in a B18C from an Integra and you've got 205hp. The engine can handle more power than a D series ever will. Then you can turbo it if thats not enough.

Intake, headers and exhaust to start. Dont know what your budget is, but a turbo is a good choice, or a swap to a Kseries or Bseries. This should be a pretty easy question to answer by yourself depending on how much money you have...

It is a typical tuner car all looks no power. What good do the tinted windows and shiny wheels do with no power. Sounds like a wannabe pimp car.

nitrous! NOS, ZEX, etc.. many companies out there..