It's difficult to recommend these Chris without looking like I'm clamouring for obscurantist connoisseur points but if you're exploring Belgian ales and fed up with the usual Trappists and Dubbels etc. I'd really vouch for these two which are peculiar, very distinctive and extremely good.
Duchesse de Bourgogne - A Flemish ale which has an almost red wine richness but isn't at all heavy. (You might have some luck ordering it
here.)
Drie Fonteinen Oude Gueuze
I'll leave it to the review to sell this one -
This bottle displayed some straight lemon zest in the nose, some malt and horse blanket notes..If you can't track down a mature Oude (old) Gueuze then almost any Gueuze Lambic will blow your mind ever so slightly, really sour and tart, fantastic beer.