I'm sure there will be several others who will have better or more specific answers than me but ideally you want to shoot for ilvl of 100 to finish the storyline all of the way to 2.55. When you finish the 2.0 story you unlock a ton of extra content. I used a combination of dungeons, beast tribe quests and hunts to build up tomes and seal to get everything upgraded. Some people enjoy crafting and can make some gear that is equal or better than the tomes gear. There is also the relic questline that can give you a very good weapon if you want to invest the time and money for it.