Neonchameleon
Legend
For the record if it's just damage output you're interested in, Chaos Bolt (from Chaos Sorcerors)* and Hand of Radiance (from Invokers)** both often beat out Twin Strike. They just aren't as focussed.There are some edge cases where Twin Strike can be edged out, but they're pretty rare. The main competition are really things like Throw & Stab, and that's more a matter of tactics and build synergy, you still want TS to fall back on.
* An average of two targets and using Sorceror statics. In PHB 2
** Three targets... In Divine Powerz