Fortunately, experience eventually proves to us all how wrong casual Sun-sign compatibility readings can be. Reducing 12 Sun signs to four "elements" makes such readings less accurate, not more so. The solution is compatibility readings with depth and detail. For this I joyfully recommend http://zodiac-traits.com.
Astrologer Nancy Fenn profiles each of the possible Sun-sign pairings, and not just (for example) Virgo/Cancer but Virgo woman/Cancer man — or Virgo man/Cancer woman. Because naturally those will differ! Each discussion is about 1,000 words long, maximizing the chances it will mirror your own situation. Fenn describes how to attract a certain sign, how much romance, passion, and friendship the couple are likely to share, and how it may end. Fenn is honest and has a sense of humor. If you like, she offers an individualized compatibility report, using both partners' birth information, for $19.95. On the site, readers share their own fascinating compatibility triumphs and woes. One of the comments called zodiac-traits.com “a brilliant site.” I think it is. And it’s easy to navigate. Five stars.
Fenn has another URL profiling natal astrological traits including Sun sign, Moon sign, and Rising Sign at http://zodiacsigntraits.com. It’s good also. Who is Nancy Fenn? She teaches online astrology courses and calls herself America’s expert on Saturn Returns (very unfortunately suggesting that the second Saturn return can be lethal if the first wasn’t negotiated well). Common sense I hope tells you that planets can’t kill anybody. Planets can’t destroy a solid relationship, either.