First job at IBM Research... career suicide?

IBM is a great company and looks good on your resume.

You're fine, OP. Yeah IBM kinda sucks but it's more about what you can accomplish and learn there than the reputation of the company. Will you be able to work on impactful, unique projects? You can be a strong candidate from an uncool company or a weak candidate from the most hip company in the world.

It is not career suicide to join IBM. It is if you stay there for a long while

Are they publishing good papers in STOC/FOCS or other first-rate conferences in your topic? Are they generating important patents?

They tried to offer a friend graduating with a bachelor's only 45k, and kept saying that it's because it's so cheap here! It's not that cheap to live near their hq. A lot of people say it's a job you take if literally no one else wants you as a ton of people work from home and hardly do anything anymore. I've often heard the words sinking ship when IBM is mentioned.

IBM research is good place for PhD. This company is consistently filing highest number of patents. If you are on product or Consulting end, story is different. Also as someone mentioned above, older corporates tend to be political as compared to new breed, so take your pick. ( Ex IBMer, recently left Watson Health )

I joined IBM Research Center in Yorktown Heights NY after PhD years ago and worked there for 2 years. Great experience and helped my career moves later on.

I spent many years at Yahoo which isn't the most "hip" but haven't felt it has hurt me at all with interviewing. Maybe just don't stay for 10 years.

Depends on the group. For CS theory (Almaden), joining IBM is extremely hard, and I would say is definitely worth it. I would also say that the bar is incommensurably higher than that for getting a SWE job at Google, MS, etc. What is your long-term career goal? Becoming a researcher or a SWE?