If a rabbit has disappointed you before: look at the arm, not the motor. A flexible or adjustable arm fits far more bodies than a rigid one, and mismatch there is the single most common reason a rabbit sits unused.
If this is your first: go shorter than you think. Insertable length above five inches stops helping and starts getting in the way of the arm reaching where it needs to.
If steady vibration goes numb on you: a flapper or tapping arm. Intermittent contact keeps registering long after constant buzz has stopped doing anything.
If you want it hands free: thrusting. The shaft moves on its own, which is the only version here that does not need you to do the work. See thrusting vibrators.
If the G-spot is the target: check the curve as well as the arm. Some rabbits are shaped to press the front wall and some just go straight in. The G-spot vibrators page is sorted for that specifically.
On lube: water based with silicone. Two motors in one toy pull on more lube than a single one, and silicone lube degrades silicone. See water based lubricants.