On big screens the transaction list has a lot of space that is not utilized:

I suggest that the columns shown here are made configurable. I would personally like the following columns:
- Debit
- Fee
- Net amount
- TxID
- Number of recipients
- Number of inputs
- Number of confirmations (right now this is rendered as a graphical indicator combined with a tooltip)
- A button column "Copy transaction details to clipboard". This is useful for copying out all of the data to document the transaction in some other place.
- Maybe a text comment for the transaction in addition to the label (which is meant to be short)
I am always unsure what the "Amount (BTC)" column means. It would help to have all three amount-based columns available. Right now I have to open the transaction details to find those values.
Maybe there are other data that can be exposed for power users as well.