If you're looking to buy Battlestar Galactica cards the first thing you need to do is make sure you're buying cards for the correct series.  Both the original series (staring Lorne Greene, Dirk Benedict and Richard Hatch) and the new series (starring Edward James Olmos, Mary McDonnell and Tricia Helfer) have had several sets of cards produced.

Battlestar Galactica Original TV Series

There are currently 5 American card sets for the original Galactica series (there are also a few sets that were produced outside of the states).

Topps 1978. Back in 1978 when the show first was on television Topps produced a 132 card set.  The set also had 22 stickers to go along with it.  These cards only contained images from the pilot (also known as the movie).  

WonderBread 1978. set. There were 36 cards in this set.  1 was inserted in specially marked loaves of Wonderbread.

Dart Flipcards, 1996. This 72 card set set was done in foil and contained a mix of photos from the episodes and technical drawings.  In addition to the base set there were 6 Gold Foil Cards, 4 "Tall Boy" cards, a Richard Hatch Autograph card, 1 mail away card and assorted promos.  A card binder (album) was also produced for this series.

Complete Battlestar Galactica, 2003.This is the first set Rittenhouse Archives produced for the show and it's without a doubt the best set made for the series.  The 72 card base set contains cards for EVERY episode of the original series and there are some great images used.  In addition to the base cards there are autograph cards and sketch cards. Other chase cards included Galactica 1980 (see below), ArtiFEX (7 cards, 6 black and white, 1 in color) and Colonial Warriors (9 cards),

Galactica 1980. There are 20 cards in this set but very few of them contain images of the main actors (Barry Van Dyke, Kent McCord and Robyn Douglass).  The Galactica 1980 set is a chase set (meaning it's tougher to put together than the basic set and you have to chase around to finish it).  The Galactica 1980 cards were randomly inserted in packs of the Complete Battlestar Galactica cards.

Colonial Warriors, 2005. Rittenhouse Archives issued another Galactica set in 2005. Another nice set from Rittenhouse, this one is character drive - and each character gets a certain number of cards in this set. This not only contains cards for actors from the original show but Kent McCord and Robyn Douglass from Galactica 1980 are also included.  As with the previous release there was an assortment of costume and autograph cards. Other chase included Casting Call (9 cards), ArtiFEX (9 cards), 2 Tribute cards (1 for John Collicos, 1 for Lorne Greene) and 1978 expansion cards.

The 1978 expansion set is very tough to put together as there are 54 cards in the set and you only get 3-4 per box.  The set looks just like the cards produced by Topps in 1978 and starts with card #133.  An image of one of the cards is shown below.

SciFi Channel Series

If you're a fan of the new show Rittenhouse Archives has made cards for you to collect and enjoy as well.

Battlestar Galactica Premiere, 2005.  This set only covers the mini series. 72 cards are in the base set.  Chase inlude costume cards, autograph cards, Roll Call (9 cards), Cylon Threat (9 cards), Quotables (9 cards). 2 sketch cards were also produced as well as 5 promotional cards.  A binder was also made.

Battlestar Galactica Season 1, 2006.  72 cards are in the base set.  Chase cards include, costume, autograph, sketch (1), in Motion (6 cards), Number 6 (6 cards), ArtiFEX (9 cards). Crossroads (9 cards). 5 promotional cards were also made.  A binder was also produced for this series.

Battlestar Galactica Season 2, 2007. 72 cards are in the base set.  Chase cards include costume, autograph, Crew Cards (9), Women of Galactica (9 cards), Rag Tag Fleet (9 cards), Alliances (9 cards), Shelter Posters (4).  The shelter posters are card sized reproductions of the 4 different posters that could be found in bus shelters to promote the series.

If that's not enough for you there are also 2 sets of game cards for the SciFi Channel series.  There are many people who collect the game cards but don't play the game.  Both sets were produced by WizKids.  The first was simply called Battlestar Galactica.  The second was named Betrayal. An image of one of the cards is shown below.