i grieved for Marcus meself. I really lied him. But I never thought of Ivanova as "hot", just admirable and a hoot in a crises. Leyta Alexander was much better looking. but when the show began to delve into people's sex lives, it cheapened itself and lost it's edge.
I looked at Ivanova as competent, fierce, indomitable and able to stand up to a crises without going all ga-ga. All admirable traits. her character was feminine without being sleazy - an officer who just happened to be female - and a good one at that.
I think that might well be part of why I thought she was hot. Also, it's a pretty good description of Mrs Mag, hold the officer part. Mrs Mag also physically resembles her except for height and eye color.
I liked Marcus and his dying saddened me, but being Marcus, he could do no other than to die saving Ivanova.
I think that is why B5 was so great, the characters always stayed true to themselves.