Interactive Java Viewer for METARs (opens with US View but click on "overview" and other areas of the world can be selected - provided by NCAR) ... An excellent site as the map is totally interactive.. areas can be zoomed in and out and METAR elements added and removed as required. Hover over obs for latest coded METAR. TAFs also available for US and USAF bases within Europe
Clickable map viewer for METARs (& TAFs) all around the world (opens with Brize Norton ob showing but click on the red/yellow dots to get other obs - provided by AllMetSat)
Another map viewer for METARs (provided by Skylink)
Current METAR's from a selection of UK/European Airports (Now requires registration)
Current METAR's for selected UK & Ireland Airports...

UPDATED : METAR's for the past 24 hours, for a selection of UK/European Airports
METAR's for the past 24 hours, worldwide

Clickable map viewer for 9/18/24hr TAFs all around the world (opens with Brize Norton ob showing but click on the red/yellow dots to get other obs - provided by AllMetSat)
Current 9 hour TAF's for a selection of UK/European Airports(Now requires registration)
Current 18 hour TAF's for a selection of UK/European Airports(Now requires registration)
Current 9 & 18 hour TAF's for a selection of UK Airports...

300mb Jetstream Forecast (Requires subscription to Met Office Aviation Subscription Service)
Met Office Mesoscale Model Cloud and Preciptiation Forecast (Requires subscription to Met Office Aviation Subscription Service)
Met Office NIMROD Visibility Forecast (Requires subscription to Met Office Aviation Subscription Service)