Silicone and TPE are both high quality sex materials.  Silicone is typically regarded as the more durable material and TPE as the most realistic.  Here are the main attributes of each material.
Silicone - Browse Silicone Sex Dolls
A bit harder than TPE but also more durable. More expensive. Easier to clean.Safe for human contact.
TPE - Browse TPE Sex Dolls
TPE is softer to the touch. More realistic ‘jiggling’ of body parts (breasts, ass, etc). The material is more elastic which allows the dolls to be more flexible at their joints. Good heat retention. Less expensive. Safe for human contactLess durable than Silicone - more care is required to clean and care for it properly.