I travelled to Gambia, like most British tourists, on a package, organized very well, in our case, by The Gambia Experience, who seem to be the best in the field and who also give something back to the country by helping schools, nature reserves etc.
Gambia is very poor and there is, in the streets, a certain amount of hassle, though more laid back than in places like Egypt. Having said that, many Gambians are very friendly and most seem to be genuinely so, albeit that you are likely to meet mostly people working in your hotel or around.
We were in the Palm Grove, a 3-4 star place on the Atlantic (actually on a lagoon...that was the main problem with it.: one had a paddle a canoe or boat 15 mins to get to the beach itself, though there was a small beach actually on the lagoon). The hotel even had its own tailor, who made me two quite good tropical-weight suits for less than £40 each (we added a bit though).
The Gambia is well worth trying out if you want sun and are happy to either stay around a hotel or perhaps go upriver (River Gambia) and watch the untold varieties of birds. Our only trip outside in a week (except to a nearby tourist-oriented craft market) was in a taxi with three other Brits, going to an excellent Lebanese restaurant (Al-Basha), located in the supposedly best area called Kololi, which is where many good hotels and several embassies etc are located.
Try The Gambia. For one thing, it's the only more or less together counry in West Africa.