First of all,

Good question!

"Bubble Bobble" (that's the correct spelling) is a reat game, even today. Perhaps more so.

 You might find several adaptations on the web, but these are all crappy (generally speaking).

Your best bet is to use MAME (Multiple Arcade Machine Emulator).

It's 100% free and can support ALL the old arcade games you can think of! The strongest point of MAME is that it actually lets you play the EXACT games, and not some "port" or "adaptation".

The game will be 100% similiar to the Bubble Bobble you grew on ;-)

basic MAME is command line based, but you can easily use "Mame32" for windows (also free):

http://mame32.classicgaming.gamespy.com/download.htm

to find "Bubble Bobble" and other games (called ROMs, as they represent the ols Read Only Memory chips on which those games were stored) use these websites:

http://romhustler.net/roms/mame

http://www.rom-world.com/dl.php?name=MAME

Direct link for downloading "Bubble Bobble":

http://www.rom-world.com/file.php?id=24292

NOTE: I believe that there's no problem using these things personally, but if u care about that sort of things, make sure u read the MAME license agreement and the Terms of Service of the rom sites.

One last thing - Why stop at bubble bobble? how bout "wonderboy", "commando", "galaga", "Ms. Pacman", "Kong fu master", "Arkanoid", "Willow", etc...?

Lots of treaures to find for MAME...

Enjoy!