I know Tiesto remixed a few popular songs by some top 40 artists...

Katy Perry- ET
Kanye West- Lost In The World
Gotye featuring Kimbra- Somebody That I Used to Know
Justin Timberlake- LoveStoned/I Think She Knows
Passion Pit- Carried Away
Calvin Harris featuring Florence Welch- Sweet Nothing
Icona Pop- I love it
Maroon 5- Not Falling Apart
Zedd featuring Foxes- Clarity
David Guetta featuring Taped Rai — Just One Last Time (Hard Rock Sofa's is much better IMO)
Jus Jack & Oza feat. Blessid Union Of Souls - Love Is The Answer (Old track, but very recognizable)

My favorite (non-trance remix) is probably his remix of Coldplay's track Paradise.

Some are pretty good, some might not work so well for your sets. I'm not sure if most of them were top 40, but they're pretty well known.

Can't really go wrong with any track that was remixed from Guetta though.