best caster wep(s)?

The biggest problem i see is the title - caster weapons.
For many years now when i hear "caster weapon" it generally applies to "weapon of enchanting" with the +5 e ^ 50% which many of us knows is usually a spear/sword/axe on a specific caster build - gd example is 55 m/no which uses -50 offhand and a caster weapon.
Going from the thread title i was expecting it to be about that rather than a type of stave or wand.
And DJ is right in saying there is no best weapon - i used to love doing 55 mo with a fiery dragon sword of enchanting just coz of its animation and if i recall i once had a celestial sword of enchanting for same reason but even tho id think its cool another player like DJ may disagree and have his own personal preference.
Infact most of gw is personal preference - if you had a survey of every person who played gw no object ( weapon/armor etc ) would have a 100% agreence and the percentages would be all different.

Staves ( staffs ) are 11-22 dmg as all non physical weapons but can have certain mods like enchanting and a few with +60hp and wands are also same dmg but dont have enchanting.Staves can have +20 energy where wand and foci gets +17 - thats not including the high energy mods.

And again as DJ said - check their bars rather than go by weapons , one 7h build for destroyer farming has 3 mesmers with shields .

Depends, when you're running some Orders team build equipping casters with spears and shields might be a Good Idea.

I choose the weapon around the build. Start with a weapon that meets requirements of the build i.e if the build has 12 in curses then ill get a weapon with q9 in curses. I'll then look at the skills and see what mods are needed, ill usually see if there is a "green/unique" weapon that fits the bill as they are cheaper and easier to get. This of course is for general use, some builds do require specific weapons to work optimally the details will always be on pvx as to what weapons the build needs.

What's best depends on your build. Conceivably, you could map out a flowchart for the following, but I can't be assed.

Pick whichever factor from the list below is most important to your build. Most factors appear only once. If one of the factors that appears twice is most important for you build, use the second-most important factor for your build as a tiebreaker.

Spear+FocusCan have 20% enchant mod. (So can staff) Can have condition-lengthening mod (for things like Technobabble). Can do physical damage (for things like Mark of Pain). Causes the AI to treat you differently. (Won't get targeted with certain anti-caster spells like Chaos Storm, but also won't get caster buffs like BiP. (Actually, you will get BiP, but you'll be treated like a paragon.)) Causes hero AI to stand a little closer to the monsters. Can have 20% enchant mod and "20% +1 attribute" mod at the same time.
StaffCan have 20% enchant mod. (So can spear+focus.) Can have the maximum attainable amount of Halves Recharge Time for all spells.

Can have the maximum attainable amount of Halves Cast Time for a single attribute line. (So can Wand+Focus)
Wand+FocusCan have the maximum attainable amount of Halves Recharge Time for a single attribute line. (dual 20/20) Can have the maximum attainable amount of Halves Cast Time for a single attribute line. (So can staff.) Can have the maximum attainable amount of both Halves Recharge Time and Halves Cast Time for two attribute lines simultaneously.** (20/20 for each)
(**This is the maximum HRT and HCT attainable at the same time with respect to both attributes. If you wanted to max HRT for both attributes, but max HCT for only one attribute, then a staff would be better.)

I kinda like the whole spear team part of one of my chars. My paragon has this team because I was throwing spears and thought why not all bring spears and us abuse splinter weapon and while I am at it a nice MoP once in a while.
20% mod on the caster who benefit from it, it's kind of fun and they use their spear more often then I thought they would.

Heroes will spend a lot of time autoattacking, so for general use I think the main thing to do is make sure they've got weapons in an appropriate attribute line so they're doing max autoattack damage. It's not going to be immense but as they're going to do it anyway you may as well ensure they're not accidentally doing half damage with it.

Other than that the weapon mods depend on the skills in the build - but heroes will only do things optimally by accident so I don't worry too much about it.
(EG recharge reduction bonuses are nice but as a hero probably won't be using abilities on recharge too often in the first place, the bonus isn't going to be used to maximum benefit.)

agreed, a hero party with all spears (preferably with caster mods) can work very well. with my Derv I run dual Splinter and an Order of the Vamp necro and the extra damage output can be surprising. I don't run Mark of Pain though, I don't like the single target, 20sec recharge