scepter is worst weapon for mesmer. sword/pistol or focus both are great. i perfer focus cause of swiftness and pull, but pistol gives more dps. if you dont want to use GS, then its staff and go with sword/pistol or focus.
There is only one word for noobs when playing DOTA 2........UNINSTALL
Used to run sword/pistol, then I got sick of switching to focus all the time for what little pathetic movement skills we have, so I just use focus all the time now.
I went from Asura engineer to Norn mesmer. Went from easiest permanent swiftness class to the slowest class in the game. From fast little legs to lumbering giant. Feels like I'm playing in slow motion.
Scepter is only viable in PvP and with a condition build, So Sword will be your mainhand.
Focus is by far the most useful utility offhand, but pistol and torch are both viable, so mess around a bit and see what you like.
Staff is probably the strongest alternative to GS, and can do fairly well with a phantasm build, so if you're looking for a combination to try out go Staff + Sword/Focus for now, and just throw some cheap pistol/torch offhands in to test out.
If you really want to switch things up, condition or phantasm builds are interesting, but honestly, nothing is as straight forward as power/precision GS builds are.
It would ideally help to know your main weapon, to know what we're dealing with.
My mesmer goes Staff / dual-sword (at the moment; was previously sword/pistol and may change back when I hit 80 and decide on final weapons), and have been doing pretty well with shattering with both sets. Although I just hit 60 (61 actually), so I'm now preparing my final build. It WILL utilize shatters, although I also want to utilize the illusions. I like leaving them up long enough for me to fire a couple skills, then shattering.
Anyway. Both the staff and sword+(sword/pistol) have a phantasm each, and an illusion each, and there are plenty of choices for a useful phantasm utility (I prefer triple-phantasm, which is why I like giving them a few seconds to act), so it's a viable way to operate. (I just need to attack GuildWiki to find the optimal build for it. So far, I am ONLY sure about 30 Illusion.)
Greatswords - for all that I dislike the mentality of people using them "for the lasers" - ARE said to be the best weapon for shatter builds. I used one briefly (to learn the skills), and found it decent enough to keep a spare for manual weapon swapping, when situations warrant it. But I prefer the sword/sword or sword/pistol to it overall.
"As the good archmage often admonishes me, I ought not to let my mind wander, as it's too small to go off by itself." -Danilo Thann
Don't underestimate sword skill 3 at making clones. It has a 12s base cooldown and can be Traited to recharge faster (I believe doubly from the clone reduction and sword reduction traits, not positive that they stack though). Both its initial effect and secondary skill use will count as a leap finisher. Also, sword clones apply vulnerability on hit. (the skill itself applies cripple and immobilize).