Start by anchoring the diagnosis: genuine, or urodynamic, stress incontinence is leakage triggered by raised intra-abdominal pressure such as coughing or sneezing, caused by a poorly supported, hypermobile urethra or a weak sphincter, with no overactive detrusor. The question asks for the best surgical option among four, so rank them by modern effectiveness and morbidity. Kelly's plication is an old anterior vaginal repair technique with the poorest durable success for incontinence and is no longer favoured. Burch colposuspension and the traditional pubovaginal sling are both genuine effective operations, but they are more invasive open or abdominal procedures. The tension-free vaginal tape places a midurethral synthetic mesh through a minimally invasive route, supporting the urethra during stress without tension; it gives high and durable cure rates with short operating time and rapid recovery, which is why it became the reference standard surgical therapy for this condition. Weighing efficacy against invasiveness, the tension-free vaginal tape is the best option.
\[\boxed{\text{Tension-free vaginal tape}}\]