There are many.
Stock sealed beams - Found on 84-87 & 90-91 cars. They're just terrible
US Ellipsoids - Found on 89-90 models. Much better direction of light overall, uses 9006 bulbs. Best platform for adding HID because the light is very focused.
Euro Ellipsoids - Found on European models. Same overall setup as the US ones, but they have a "smilie" at the bottom of the light, which scatters the stray non-directed light towards the ground directly in front of the car. Really not much of a difference, save for the use of H1 bulbs.
Hella H4 - Aftermarket, uses reflectors to aim light. Different aiming than the Ellips, but overall throws more light onto the road. Not as good for HID though, as the light is too scattered.
Cibie - Aftermarket, less known, but has the potential to be the best bang for the buck. It uses H1 bulbs, so the wattage you want can be dialed in. It retails for under 100USD.
...and those are the main ones. For what it's worth, I have Hella H4's on my car and love them. The difference over my old sealed beams is almost funny. Note also that any ellipsoids will require some slight wiring/harness modification, something that I wasn't willing to do. The Hella's and Cibie's bolt right in.