I don't think there's an "Ideal" podcast for me. Or at least, not an ideal formula. I love the Hello Internet podcast with CGP Grey and Brady Haran, which is sort of "2 guys talking" genre, and I love the Roundtable Podcast, which is cohosted by 4 indie game youtubers. Let's call that "4 guys talking" I also love the Invisibilia Podcast, which was an NPR thing and is getting a second season. I can't recommend it enough - It's like radio lab but hosted by two girls and is all about the invisible parts of ourselves. The "Ideas" Radio show with Paul Kennedy on CBC is put out as a podcast and it's been amazing for 20 years +. "Quirks and Quarks" with Bob MacDonald (Once hosted by none other than David Suzuki) is similarly long standing and AMAZING. All of them are vaguely centred around in depth discussion of specific interests - Except for Hello Internet, which is In depth discussion of wide ranging interests, and occasionally nothing at all.