The only other tallow based soaps that I like as much as Cella are the new RazoRock Linea Officina Artigiana soft soaps (Chianti Lavender fragrance in particular) and the Valobra stick. Among vegetable soaps I certainly need to mention Martin de Candre and La Toja Manantiales.
If you like Cella, RazoRock makes an amazing product along similar lines. I am in the middle of experimenting with Vitos which performs nicely without the "cella-ey" smell that's mentioned a lot in reviews. $26 nets a 1kg brick.