I have mammillaria. Apart from a few species, the flowers aren't large, but they flower in abundance, and over a long season (several are in flower now), and the spine formation is very attractive.

We also have rebutia (easy to flower, with abundant flowers over a shorter season), gymnocalycium (bigger and fewer flowers, but again attractive plants when not in flower), sulcorebutia (like rebutia, but more attractive spines), lobivia/echinopsis (beautiful flowers, some plants with a few huge flowers, others with more smaller flowers in beautiful deep reds and pinks, some of them on attractive plants), and a few plants of various other genera.

What was your old one like? And what do you like in a cactus - are you after flowers or an attractive plant?