If you want flexible AND awesome sound: Nemesis. There's not much this delay can't do and do well.Pretty much that. I could buy a Timeline but I think it will be overkill when everything I want it's just a digital delay for leads.
I would go the other way around and suggest a brighter delay pedal for big, fat leads. If you're on a budget, the TC Flashback series are my top suggestion. I would also very seriously consider the Wampler Tape Echo (listen to Burgs demo, when it's used with the Sovereign, for reference).
I also own the Carbon Copy and would certainly suggest it for leads, but not for high gain ones. IMO, with high-gain a dark delay tends to get lost in the overall mix. I generally use it for low-gain / med-gain lead sounds.
Used Boss DD3 in the loop and you're done.
digital is what you want for that. DD3 is perfect. there are digital delays w more features but none that sound better.
The Carbon Copy is stellar for leads, is analog and can be had at $80 used. It was made for high gain bc it is darker and stays behind the note, never muddying things.
For lead, it's hard to beat a Carbon Copy.