Another vote for Port Charlotte 10.
If you want something a bit cheaper then Ardbeg 10 is usually a decent standard in £40 range.
If you're going up a bit in price and want something a little different then the Signatory Bunnahabhain Staoisha 9yo from a Pinot Noir cask is very nice:
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It's not earth shattering but the 10yo Glenfarclas bottled for MOM is decent value for under £50, bottled at 55%.
Think I only paid around £40 for it on an offer but still only £48
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