New Frontier started out great but I didn't even read the last three or four novels, it really went downhill for me.
Voyager, I've only read the relaunch starting with Full Circle, everything before that I can't comment on.
As for the Typhon Pact, it's not so much a series since the novels are not set on one specific ship or deal with one specific crew. They deal with several of the ships and crews we know and love, as they have encounters with several of the members of the Typhon Pact. That's why they were published under that banner. So, Seize The Fire for example, is really a Titan novel.