Events -- Dunno..but there are a couple of Event-to-thread mods here.
Picture Gallery -- Photopost/Photopost vBGallery - vBGallery is to be $60 apparently.
JukeBox -- vBRadio? ZeroTolerance's hack was pretty fun.
Links - No idea. Haven't played around with these.
Downloads -
www.thevbgeek.com - GeekMart/Geeker - Commercial under $50.
Friends(Hi5 type) - Dunno.
Betting with virtualcash system [already installed arcade for flash games] - vBookie - available here.