Followup - all trades I could find with 1st rd/major prospect for veterans (not my headache for your headache, i.e. Drouin, etc):
Summer trades:
9/13 18 San Jose: (Florida) 2019 2nd, 2020 1st, 2021 2nd (f resigned, 1st if resigned and they go to finals) for EK
9/10/18 VGK 2019 2nd, Tatar, Suzuki for Pacioretty (no conditions, which tells me Vegas knew they could resign him)
8/2/18 Buffalo 2019 2nd, 2020 3rd, Pu for Skinner
7/1/18 St Louis 2019 1st, 2021 2nd, Thompson for ROR (27)
11/5/17 Nashville 2018 2nd, Girard, Kamenev for Turris
6/24/17 Calgary 2018 1st, 2018 2nd, 2019 2nd (cond) for Hamonic (27)
6/23/17 Saad for Panarin (1 year)
6/23/17 Arizona 2017 1st (#7) and DeAngelo for Stepan (27) and Raanta (28)
6/23/17 St Louis 2017 1st, 2018 1st for B Schenn (26) (and taking Lehtera's two years)
6/23/17 Pitt 2017 1st and Sundqvist for Reaves and 2017 2nd
7/18/16 Ottawa 2018 2nd, Zibanejad for Brassard
6/20/16 Toronto 2016 1st, 2017 2nd, for Andersen
7/1/15 Pitt 2016 1st, Kapanen for Kessel
6/30/15 San Jose 2016 1st & Kuraly for Martin Jones
6/26/15 Edmonton 2015 1st, 2015 2nd for Griffin Reinhart (21) (#4 draft pick)
6/26/15 Buffalo 2015 2nd, Zadorov, Grigorenko, Compher for ROR (24) and Jamie McGinn (27)
6/26/15 LA 2015 1st, Colin Miller & Martin Jones for Lucic (27, one year)
6/26/15 Calgary 2015 1st, 2015 2nd, 2015 2nd for Hamilton (22)
6/26/15 Buffalo 2015 1st for Lehner
10/4/14 NYR 2015 2nd, 2016 2nd for Boychuk
6/27/14 Anaheim 2014 1st, 2014 3rd, Sbisa, Bonino for Kesler (30), 2015 3rd
TDL trades [boy do some teams grossly overpay for a slight improvement in their odds]
2/25/19 Winnipeg 1st for Hayes rental
2/24/19 Buffalo (San Jose or St Louis) 1st for Montour (25)
2/23/19 Dallas 2nd, 2020 3rd (1st if resigned) for Zuccarello
2/22/19 CBJ 2019 1st (2020 1st if resigned) for Duchene
1/28/19 Toronto 1st for Muzzin rental
2/26/18 TB 2018 1st, 2019 2nd, Namestinkov, Howden for McDonough and Miller
2/26/18 VGK 2018 1st, 2019 2nd, 2021 rd for Tatar
2/26/18 San Jose 1st 2019 (cond on resign) for Evander Kane
2/26/18 Winnipeg 1st for Stastny
2/26/18 Nashville 2018 1st for Hartman
2/25/18 Boston 2018 1st, Spooner, Lindgren for Nash
2/17/17 Wash 2017 1st, 2019 2nd (cond) & Sanford for Shattenkirk
2/26/17 Minn 2017 1st, 2018 2nd for Hanzal
2/18/16 NYR 2016 2nd, 2017 2nd for Eric Staal
2/25/16 Chicago 2016 1st for Andrew Ladd
2/22/16 San Jose 2017 2nd, 2018 2nd for Roman Polak
3/2/15 TB 2015 1st, 2015 3rd, Gudas for Coburn
3/2/15 Boston 2015 2nd, 2016 2nd for Brett Connolly
3/1/15 NYR 2016 1st, 2015 2nd, John Moore, Anthony Duclair for Yandle
2/28/15 Chicago 2015 1st for Vermette
2/25/15 LA 2015 1st for Sekera
2/15/15 Nashville 2015 1st & Leipsic for Franson & Santorelli
2/11/15 Dallas 2016 1st for Enroth