You'll want the lancer levels to get blood for blood for every dps class. Lancer is pretty easy to get into especially since they took out the positional attacks. The "optimum" skill rotation at 50 can be kind of ridiculous though.
The easiest overall is probably archer/bard because of mobility.
The easiest to solo and start with may actually be arcanist -> summoner because you get a pet and a basic healing spell. The attacks are pretty simple but you need to pay attention to other things (pet health and actions) as well.
Thaumaturge has a really easy attack sequence but can be very squishy on its own.
Monk is fun but complicated with lots of different positional based sequences.