#1 Jack Grealish (Aston Villa)

Jack Grealish is a 23-year-old attacking midfielder who currently plays for Aston Villa in the Championship. He represented Ireland's national team up until their U21 side, before making the switch to play for England's U21s instead.
Without a shadow of a doubt, Grealish is by far the best player in the Aston Villa squad right now; he pulls the strings for the side every week, ensuring that his teammates are getting service and that he, personally, is scoring every so often, too.
What makes this transfer a strong possibility is the fact that Villa don't look as if they're going to get promoted to the Premier League anytime soon. They might be close to the playoff positions, but even if they do manage to miraculously get up, the way the team currently plays is bound to send them straight back down. Consequently, a player of Grealish's calibre will want Premier League action, which Spurs are able to offer.
Another factor that makes this more likely is his affordability; Grealish has a price tag of around £25m - chump change for a club of Spurs' size.