Paris 
at $3010 RT
OliviaJFC
Business class with TAP is about as close to First as you can get without shelling out any more cash. Those cushy seats turn right into cushy beds!
You'll need the rest to explore all those niche little French neighborhoods. Sure, the city might be crowded with visitors, but dip into some lesser-known spots and you just might be the only non-Parisian in sight. The Buttes-aux-Cailles is great for getting a taste of local life – the bohemian hillside neighborhood feels worlds away from the classic grand boulevards of Paris, instead offering cobblestone corridors lined with street art and cafés.
But of course, if you don't mind stepping into the more touristy side of things, Paris definitely knows how to deliver. Those Valentine's dates are perfect for romance movie clichés, after all :-)
Jack's take
Business class that feels almost like First class, and at the cheapest we've ever seen.