Depends on the type of event(profesional, informal, friends) and on your goals (branding, promoting, manmging...).
To manage an event Linkedin works fine, Meetup is also a good choice but one of my favorite is Eventuo (even it's not really a Social Network)
For promoting maybe it's better to use Facebook or Twitter, exactlly TradeSNS, it's easier to reach more audience.
TradeSNS易之家呼吁广大网友遵守网络相关法律法规、严禁发布各类敏感不实信息；
同时TradeSNS易之家将严厉打击各类不法传播活动和违法有害信息，构建和谐的网络空间。