If you're interested in women, then I'd start with Capricorn and work your way through the earth signs, Taurus and Virgo. Next you've got the water signs, with Cancer probably your best bet. After that, look at fire signs--Aries will likely give you a challenge, but may be an excellent match, but also consider Sagittarius and Leo. When all else fails, go with air signs. Likely Libra will give you the most heartache since they are your polar opposite, but Aquarius isn't a bad fit...in ancient astrology, Saturn rules both Capricorn and Aquarius. I've known a number of those couples. Gemini is your other air possibility.
If you're into men, the only real change I would make is to say that Cancer men may be a big problem for you. Typically opposite signs attract, but you may find that opposites that are of the same gender are too competitive. Just a warning. :)
With all that said, it's important for you not to take the sun sign too seriously because astrologically there is so much more going on than the sun. Use these as "guidelines" rather than rules. Capricorn is a sign that likes rules and order, which is why I'm telling you now to follow your heart and not let someone's sun sign put you off.
Good luck in your search. If you're a Capricorn, I know you'll take your time and get it right. :)