from Shell.
Well, my favourites are:

• Timothy Taylor ‘Landlord’ bitter (that’s the one your dad had)
  
• Oakham ‘JHB’
  
• Deuchars ‘IPA’
  
• Crouch Vale ‘Brewers Gold’
  
• Fullers ‘London Pride’, ‘Discovery’ or ‘Honey Dew’
  
• Hopback ‘Summer Lightening’
  
• The whole range of Meantime beers (brewed in Greenwich)

There are so many though, and lots of smaller regional breweries. If they are REALLY interested in beer, the best book is the Good Beer Guide, available in most bookshops!