This is the first form achieved.  When DBZ first began it was stated that no Saiyan had achieved SS status in a few millennia... Vegeta and Kakarott changed that!  Then their sons all followed right behind them.

The Saiyan in question will:

• have hair that turns golden

• Their eyes become green

• have an energy the surrounds them

• become stronger than normal Saiyan levels

the 5 major Saiyans in the saga achieved this level in this order: Kakarott, Gohan, Vegeta, Trunks, and Goten.  Also in Future Trunks' timeline he achieved it.

The Saiyan in question will:

• bulk up a little more

• grow a little bit longer hair

• have an ever stronger presence of visible energy

Gohan was the first to achieve this during the Cell games.  Later Vegeta and Kakarott followed and reached it.   Gotenks did as well - the boys (Trunks and Goten) did not individually reach it but together they did.

This is visually disturbing to me.  I love all the extra hair flowing but uhm, - no eyebrows?

The Saiyan in question will:

• grow hair down to the calves (I cant even begin to imagine how much hair Raditz would have had since he started off with that much!)

• the eyebrows disappear

• the forehead seems to protrude more

• have greater speed and power than the previous forms

• have a different looking energy surrounding them

Kakarott and Gotenks are the only 2 to achieve this level and it was done during the Buu saga.

There is a huge controversy around this form.  Technically it wasn't part of DBZ - it appeared once Akira stepped down and DBGT was created by others.  Who cares?  Our Saiyans do it and that's good enough for me.  And honestly it's GT's only saving grace.  *whispers in your ear* It's what I consider the most visually appealing as well.

The Saiyan in question will:

•  grow the hair on the head a little longer  

• they sprout red fur all over their body except for the mid-chest, neck and facial area.

• The TAIL comes back (yeah!!)

• the lines around the eyes are more defined and intense.

• obviously become much much stronger.

Vegeta and Kakarott were the only 2 to achieve this status

I will obviously receive some flack here because technically Mystic is not a form of the Legendary Super Saiyans - HOWEVER since our first little half-breed DID accomplish this then I dont feel as though it should be overlooked.  Gohan learned this on the Planet of the Kais.  It awoke some hidden strengths within him.  He does NOT go Super Saiyan in this form as it will destroy the planet if he exudes that much power.  

Now comes the big question... how powerful IS this level?  Well, its never stated for sure but the general consensus, and the implications from the show, is that its stronger than SS2 and close to SS3.  Whether or not it is the same as SS3, I dont think so.  Based on my own research and judgment of the fighting skills and techniques I say its just a hairs-breath below SS3 - and I mean BARELY below it.