The vehicle/pax ferry across to Kissi is a true "African" experience - it is cheap, noisy, full and even with a "VIP" seat just a wooden bench. On arrival across the estuary you then have a slow journey (in impossible traffic) to where the hotels are (most are at Aberdeen). The alternative is a speedboat or fast ferry service across to Aberdeen. Seacoach Express is the best service (see their website) - it costs $40 and takes about 30 mins. NB in stormy weather, the estuary can be rough...
The erstwhile (Mil 8) helicopter service stopped many years back; there was a hovercraft service (an old Isle of Wight one) which has come and gone several times (but is not operating now).
The Radisson Blu at Mammy Yoko, is a good hotel which is close to the seacoach terminal and quite a few nice restaurants. But there are other good hotels around Aberdeen and also there is the Country Lodge a few miles away at Hill Station with commanding views.
Lungi Hotel is pretty grim but would probably be bearable for one night - certainly not for longer.