$wpdb->prefix vs $table_prefix

Personal preference. I tend to use $table_prefix, but that’s because I’m used to it. And it’s unlikely to vanish into deprecation hell, considering its purpose in wp-config.php. But one should probably consider $wpdb->prefix more in line with current WP coding practices.

I’m fairly sure $wpdb->prefix made it’s first appearance with 2.0.1. I seem to recall a personal bug hunt related to it.