This is a major list of Feed Aggregators / RSS Readers supporting HTTPS URL and/or HTTP Authentication.

RSS Reader / Feed Aggregator HTTPS/SSL HTTP Authentification
SharpReader Yes No
NetNewsWire Yes Yes (through URL)
NewzCrawler No Yes
NewsGator Yes Yes
AmphetaDesk No No
FeedDemon Yes Yes (through URL)
Radio Userland Yes Yes (through URL)
Synderalla No No
RSSOwl Yes Yes
Vienna (mac only) Yes Yes

Can you suggest new entires for this list?