Conjunction is the Third best position you can get. Unfortunately you can not get all of your signs 100% Trine with someone, or at least I have yet to see it. Conjunction is Leo with Leo. Trine is the best and Square would be worst… Opposing along with Conjunctions are truly the last position I would consider. Fire and Air together, Earth and Water together; any other exceptions are really inadvisable. This is in looking for a partner or friends, not looking at aspects in you own chart; that is different.

The trine(120°) is the relationship of one sign to those four signs away from it on the wheel(such as Aries to Leo, or Aries to Sagittarius), and the sextile(60°) is the relationship of one sign to those two signs away on the wheel(such as Aries to Gemini, or Aries to Aquarius). Both the trine and sextile are considered as non-critical or secondary aspects because of their generally easy or free-flowing natures. This however, does not make them any less important than the first group. It would be like saying that the signs of Gemini and Aquarius (representing the sextile) and Leo and Sagttarius(representing the trine) are less important than Aries and Libra(representing the conjunction and opposition respectively) or Cancer and Capricorn(representing the square). In astrology no one sign is any more important than another and therefore neither should any of the aspects be either.

Wiki says:

Conjunction

A conjunction (abrv. Con) is an angle of approximately 0-10°. An orb of approximately 10° is usually considered a conjunction, however if neither the Sun or Moon is involved, some consider the conjunction to be a separation (orb) of only about 0±08°. This is said to be the most powerful aspect, intensifying the effects of the involved planets mutually — and being a major point in the chart.

Whether the union is to be regarded as “positive” or “negative” depends upon what planets are involved: Venus, Jupiter and the Sun, in any possible combination, is considered the most favourable scenario (and all three actually met on November 9–10, 1970, for example), while the most unfavourable configurations involve Mars, Saturn, and/or the Moon (with all three conjoining on March 10 in that same year). If the planets are under stress from other configurations, then the conjunction will be said to intensify the stress. When a planet is in very close conjunction to the Sun it is referred to as cazimi; when a planet is moderately close to the Sun, it is said to be combust. The Sun and Moon are in conjunction monthly during the New Moon.