What Time Is It? is the best Time album IMO. Vanity 6 is a classic too, was upset when she passed away a few months ago, hard to believe Prince would join her shortly afterwards
1999 of course in the US was where it all truly began for him on a commercial level. That was the earliest I remember because my older sister loved him and had the cassette and I remember loving 1999 and Little Red Corvette but she never played anything post-Delirious around me, and as I got older and got a copy of my own, I understood why
To be fair, for an album like that to be as successful as it was was very impressive since outside of the three big hits, it wasn't really a very commercial album and plus most of the songs were 6-9 mins long at a timee where 3 minute pop singles ruled the roost.