Here's the biggest and real ships I've found. Not in order.

-Spottedleaf x Longtail [not big]

-Darkstripe x Longtail

-Crookedstar x Bluestar [not big]

-Jayfeather x Stick

-Tigerstar x Ravenpaw

-Jayfeather x Half Moon

-Firestar x Spottedleaf

-Hollyleaf x Fallen Leaves

-Dustpelt x Sandstorm

-Lionblaze x Icecloud

-Nightcloud x Squirrelflight [not big]

-Firestar x Cinderpelt

-Bluestar x Potato

-Tigerstar x Bluestar [not big]

-Firestar x Greystripe

-Brambleclaw x Ashfur [not big]

-Dovewing x Icecloud

-Lionblaze x Foxleap [not big]

-Bramblestar x Jessy

-Blossomfall x Ivypool [not big]

-Mosskit x Snowkit [not big]

-Swiftpaw x Brightpaw

-Lionblaze x Honeyfern