Most people are reduced to tears at 300,000 SHUs.
For your reference, here are the rough figures of all the various chillies.
| Chilli Name | Units (in SHU) |
|---|---|
| Naga Morich | 970,000 SHU |
| Naga Jolokia | 850,000 SHU |
| Red Savina | 350,000 to 577,000 SHU |
| Habanero's & Scotch Bonnet's | 100,000 to 350,000 SHU |
| Chiletepins, Thai & Birds Eye | 50,000 to 150,000 SHU |
| Piquin, Cayenne, Tabasco & Rocoto | 30,000 to 50,000 SHU |
| De Arbol, Aji's & Shipkas | 15,000 to 30,000 SHU |
| Serrano | 5,000 to 15,000 SHU |
| Jalapeno, Mirasol & Hot Wax | 2,500 to 5,000 SHU |
| Anaheim, Rocotillo, Sandia & Cascabel | 1,500 to 2,500 SHU |
| Ancho, Pasilla, Mulato & Espanola | 1,000 to 1,500 SHU |
| Cherry, New Mexican | 500 to 1,000 SHU |
| Bell Peppers & Pimentos | 0 SHU |
Updated [Feb 24 2007]: Thanks to thechileman, I have updated the name of the hottest chilli.