As described in this post, it's best if witnesses especially top witnesses also run seed nodes. So I unvoted these witnesses who were top 30 but I'm not aware of that has an active seed node running: 
Hive account@arhag, 
Hive account@clayop, 
Hive account@witness.svk, 
Hive account@anyx, 
Hive account@bhuz, 
Hive account@complexring, 
Hive account@good-karma, 
Hive account@busy.witness, and voted for 
Hive account@delegate.lafona.
//Edit: I put 
Hive account@ihashfury on my waiting list but not voting list since it's a bit inactive.
//Edit 2: voted for Hive account@good-karma, Hive account@bhuz and Hive account@clayop again after got more info about them; and 
Hive account@chitty is on my waiting list now.
//Edit 3: factors that may affect my witness voting at present (may be subject to change): produces blocks stably, running a seed node, working on a project / is active ( price feeds / SBD policy / version upgrade / post / comment / chat and etc ).
//Edit 4: voted for Hive account@complexring.
//Edit 5: voted for Hive account@anyx.
//Edit 6: unvoted Hive account@complexring because he's running version v0.17.0 for block producing, which is not released yet.
//Edit 7: voted for Hive account@complexring again as he has came back to v0.16.
