I'll join those recommending the Tango, with a disclaimer. The best praise I can give the Tango is that I now own two and am seriously considering a third, because I cannot bear the thought of being without a fully powered one, ever again. It is the only clit vibe that works for me quickly enough: under 10 minutes every time thus far, usually just 5, to orgasm.
Your mileage is likely to vary, though. The reason the Tango is my personal favorite is a combination of age (50+), illness (high blood pressure) and medication (beta-blockers), which all together have lead to increasing difficulties in coming. I've had a great deal of help from other toys before my Tangos (the We-Vibe Touch is still one of my favorites, as are the Lovehoney Humdinger and the Power Play 7 Function Classic, and the Motorhead Overkill). The Tango is clearly in its own class, though -- no other vibe really compares to it, in my (admittedly still fairly limited) experience.
So if your sensitivity is lowered due to age, or a medical condition and/or its medication, the Tango can be great. If on the other hand you have found some of the strengths or patterns of e.g. a Rocks Off 80mm bullet uncomfortably strong, it may be wiser to skip the Tango and maybe consider instead e.g. the Touch, which has the same motor = the same vibrations as the Tango, softened by the surrounding smooth silicone.