Obsidian Shards -
http://wiki.project1999.com/Obsidian_Shard
Acid Etched Warsword - At 37 -
http://wiki.project1999.com/Acid_Etched_War_Sword
Polished Granite Tomahawk -
http://wiki.project1999.com/Polished_Granite_Tomahawk
If you’re twinkled and can loot it - Infestation -
http://wiki.project1999.com/Infestation
Glaive of Marltek -
http://wiki.project1999.com/Glaive_of_Marltek
Goblin Skull Crusher -
http://wiki.project1999.com/Goblin_Skull_Crusher
@30 Scorpikis Claw Impaler -
http://wiki.project1999.com/Scorpikis_Claw_Impaler
These are pretty much your aggro weapons pre lvl 40. After that Frostbringer is primary, maybe get infestation, or go for Trollics Skean. Then from 46+ the options start opening up more.
That said, pre lvl 30 or 40 your best aggro will just be investing in good ratio/dps weapons. Your aggro will be bad regardless.