The Viscount is on my list, probably 1st. Lasts very long, good range for the timeframe (even at the end, in the 90s), good speed, etc. No other plane is as versatile as this one. Sure, it has 3 pilots and 4 engines (compared to the 2 of the F.27, HS 748 and NAMC), but it's worth it.
Now, for the others, I'm not sure, as it mostly depends on the context. Though I'd need to mention the 732. Way more resilient than one might think, even if it lacks range in the 2nd half of its life compared to its newer competitors.
The Britannia is also very nice, as it has 2 very distinctive config, with the 75 pax and 120 pax. Makes it both a good LH plane and an average long range medium capacity A/C. The advantage here is that it saves one fleet slots, and thus avoids the costs of one renewal. Not many types can do this.