Clearly we all have our favourites places on Bali, too many to choose from.
Perhaps the location should be dictated by the type of diving that you want to do after the Paradise Dancer.
Muck, general macro, and good walls with quiet locations I would suggest North West corner - PJ, menjangan, secret bay..
Coral encrusted wreck, some macro, busy - Tulamben (USS Liberty wreck)
Candidasa some good current diving close by - Nusa Penida, Tepekong, Manta Point (fairly reliable - possible Mola Mola at the right time).
Nusa Penida, Tepekong etc can easily be dived from any of the main areas in the south (sanur, nusa dua, seminyak etc - or even Kuta if that's your thing!) - personal preference would be a small private villa in Seminyak rather than Sanur - some good restaurants, great sunsets..
I can recommend Blue Season Bali who can also put a package together for you including diving, travel, accommodation - have used them 5/6 times in the last few years usually pre & post cruise on Paradise Dancer, Komodo Dancer, Pelagian etc. We have a Menjgangen trip booked after our Komodo Dancer cruise this November. See their suggested itineraries and adjust to yourself..