UK: Depends on candidates and tactical issues, but not Conservative. LDs, Labour, Nationalist, diverse indies...
N. Ireland: Has STV so I'll list in order: Alliance - SDLP - SF - UUP (unless anti-agreement) - DUP - TUV/any anti-agreement UUPers still left
Wales: Blaenau Gwent Independents.
No really, see UK.
Scotland: Ditto.
Ireland: Has STV so I'll list in app. order (but depends on candidates to larger extent than can be shown here): Greens - Labour - sane FG members - sane FF members - SF - average or worse FG members - average or worse FF members - PD
Norway: DNA
Sweden: Greens, I guess
Finland: Not sure
Poland: Socialists
Greece: Syriza
Italy: wide range of minor left wing parties to chose from. PdCI sounds nice.
Switzerland: Greens (tactically SPS in smaller cantons)
Austria: Greens
Germany: Left or Greens
Holland: Socialists or Greens
Belgium: Greens
France: Gauche Plurielle
Spain: PSOE in most provinces, ERC in Catalonia, possibly not PSOE also in some other provinces
Portugal: What's it called? The newer far-left party. Socialists where that makes tactical sense.
Cyprus: AKEL
Malta: AD
Israel: Hamas.
Turkey: AKP or Kurds
India: Depends on tactical considerations, candidates. Not BJP or allies.
Pakistan: Awami Party
Japan: Democrats
Australia: Preferencing Labor over the Coalition, but probably third party.
NZ: Greens
South Africa: My relatives there voted ANC last I knew. (Which demonstrates that they must be living in KwaZulu-Natal.
) I'll follow that advice, for now.
Canada: NDP
Quebec: Also NDP
Puerto Rico: Popular Democrats
Jamaica: PNP
Mexico: PRD... at least most of the time...
Venezuela: Chavez over any US-supported opposition; any moderate non-US-supported opposition over Chavez
Brazil: PT
Peru: Would have held my nose and voted for Alan Garcia last time around... twice.
Ecuador: Chavist
Bolivia: Morales
Uruguay: what's it called again? Frente something.
Argentina: They still have real parties in Argentina? I think not...
Chile: Socialist