For anyone who cares, here's what I think:
AL - Steve Marshall is running for a full term, but things could get interesting in the primary since he was appointed by Bentley.
Safe RAZ - Mark Brnovich is running for reelection. January Contreras seems to be a credible candidate though, and Brnovich only narrowly won in 2014.
Leans RAR - Leslie Rutledge is running for reelection. Nothing interesting here.
Safe RCA - Whether Becerra runs for reelection or not,
Safe DCO - Coffman is running for governor, so the race looks a little easier for Democrats, but still
TossupCT - An open seat. This could be an opening for the GOP, but anti-GOP backlash and the Dem-leaning nature of CT makes me think Dems are favored to hold it
Leans DDE - Matt Denn is not running for reelection. While it might look like an easy D hold, it could end up being a dark horse for Republicans.
Likely DFL - An open seat that will be hotly contested.
TossupGA - This is a pseudo-open seat, so it could potentially be competitive.
Likely RID - Moving on.
Safe RIL - This is now an open seat. Dems are favored to hold it, but the GOP has an interesting candidate in Erika Harold
Likely DIA - Tom Miller is running for reelection, and should be in fairly good shape, despite the hard-GOP turn of IA in 2016
Likely DKS - This one looks pretty safe. Derek Schmidt is from the moderate wing of the KS GOP, so he can distance himself from Brownback
Safe RMD - Frosh easily won in 2014 even as Hogan was winning.
Safe DMA -
Safe DMI - An open seat.
TossupMN - Swanson is running for reelection now, so she should be in pretty good shape to hold it.
Likely DNE -
Safe RNV - See Colorado. Ds have a decent bench here.
TossupNM - Balderas isn't going anywhere.
Safe DNY -
Safe DND -
Safe ROH - DeWine is term-limited and both sides appear to have strong candidates.
TossupOK -
Safe RRI -
Safe DSC -
Safe RSD -
Safe RTX - Ken Paxton is under federal indictment, and Democrats have a credible candidate in trial lawyer Justin Nelson, but it's a tough race for a Democrat.
Likely RWI - Again, this will probably depend on how the Governor's race turns out. Schimel is running for reelection, and Josh Kaul, a former federal prosecutor, has declared for the D nomination, and seems like a serious candidate.
Tossup