(edited by Professor Sprout.1560)
Best class/stats for solo dungeons/fractals?
Best stats are Berserker for dungeons and lowlevelfractals and viper/sinister if you use a condi-class and go higher level fractals. If you can survive in these stats, naturally.
The classes most used for soloing are elementalist, who has the highest solo-damage, and there are lots of videos for nearly any dungeon in the game or warrior, who is damagewise on the higher end for solo and sturdy enough for some mistakes.
But if you’re fine with engineer, he should also be a good soloclass, as he can stack might and vulnerability and his damagepotential is rather huge, but he has a complex rotation. gear should also be vipers(or sinister?) or bersi, depending if you want to go condi or direct damage. But thanks to his versatility, he can solve a lot of situations and offer you the chance to learn the encounters in a new way
For solo Raids, there is a theoreticall possibility of doing it with mesmer, but even valeguard would take hours, and be really unfogiving, as you have to be invincible for every green circle, on top of dodging the attacks and doing the mechanics of the boss and healing yourself. Also due to having really low dps Mesmer is not a good soloclass in general, he can do cool things, but takes his sweet time.
Solo classes:
Dungeons: All classes, know your class and all can do it. The build will depend on the dungeon and the path. Bevare a few cant be soloed, like CoE and some will take more skill then others.
I recommend on starting with an easy one like CM P1 or P3.
Fractals: same same same
Raids: I have seen a duo escort, and a trio VG, but a solo.. VG can as stated in teory be soloed. But it will take hours without doing any mistakes. GL ^^