I would assess the current traffic patterns to help decide. When people enter/exit your kitchen, is it more natural to leave via the aisle on the left of the island or the right? Would losing an aisle cause congestion or be aggravating to have to walk around all the time? Without knowing traffic flow and what's beyond the kitchen, I don't see how anyone can answer that for you.

Could you post a picture of the floorplan for that floor so folks here can assess traffic flow issues when responding?

We need actual measurements to be able to help with that.

post the 2-D layout, these look almost the same to me the way you posted

Do you need that island with counter seating, considering how close your eating area is?

I know you didn't ask for layout help other than the peninsula vs island, but...

Is that your refrigerator against the wall? If so, to be able to open the doors and, possibly, interior drawers fully, you will need a few inches b/w the refrigerator and wall --or-- reduce the wall's depth so it's no deeper than the refrigerator's carcass/box. Unless the refrigerator is a built-in refrigerator, the doors must extend past all obstructions (walls, cabinets, counters, etc.).

If that's a pantry, then I think your best option would be to reduce the depth of the pantry so the wall is no deeper than the refrigerator box (if it's a standard-depth, then 30" or so; if it's a counter-depth, then 24" or so - check the specs of the refrigerator)

If you post a measured layout, you might get even more options from folks here - many think "outside the box" to come up with creative designs. If you would like help or just more options to choose from, then post a layout with the widths of all walls/windows/doors/doorways and the distances b/w the walls/windows/doors/doorways. Indicate where each doorway leads and the swing of the doors. Finally, a full-floor sketch would be very helpful as well.

Here is a link that might be useful: FAQ: How do I ask for Layout Help and what information should I include?

Option 1 :)

I think you'll get more storage (and more accessible storage) with the first plan.

Is your island going to be about 5' long? You might want to consider slightly rounded corners...your hips will thank you! LOL