Growing up in rural Hampshire / Dorset borders, they were all green Bristol double decks (Hants and Dorset) in late 1960s and early 1970s. Hardly ever travelled by bus.
But when we occasionally went into Bournemouth I always wanted to go on the yellow open tops, they were much more modern, probably were Atlanteens
The Open top fleet from the mid 60s onwards were Daimler Fleetlines. Though Bournemouth Corporation also operated close top Atlanteans.
Which neatly brings me to my favourites:
1) the aforementioned Daimler Fleetlines CRU180C - CRU189C.
2) the two MH Cars Belfast bodied Fleetlines ALJ340B and ALJ341B
3) Shamrock and Rambler Plaxton Bodied Leyland Leopard KAD347V - I saw this coach when it was first delivered prior to entry into service.