I am assuming your data has two columns in addition to other columns.
| .... | .... | BlogId | OtherUserId | ... | ... |
Let's say the OtherUserId corresponds to a Like.
Then you can do a GroupBy on the BlogId and count on OtherUserId. This will give you a distribution of how many Likes each blogId has received. You can then sort this table in descending order to see the highest value on the top. The highest count is the mode. It is possible that there are multiple modes, and it's something you may discover as you explore the data.