One of my main targets was the Monarch A300s before they are retired, so I was pleased to get both:
G-MAJS:

G-MAJS Monarch A306 at Gatwick EGKK by AeroPics, on Flickr
And G-OJMR:

G-OJMR Monarch A306 at Gatwick EGKK by AeroPics, on Flickr
Continuing with the Monarch, theme, here's one of many A321s which arrived:

G-OZBZ Monarch A321 at Gatwick EGKK by AeroPics, on Flickr
Which will shortly rep;lace the last few 757s:

G-MONJ MON B752 291213 EGKK by AeroPics, on Flickr
easyJet is undoubtedly 'King' at Gatwick, now with almost as many A320s as A319s:
A nice new one with sharklets:

G-EZWN easyJet A320 at Gatwick EGKK by AeroPics, on Flickr
And, what is affectionately known as 'The Carrot':

G-EZUI easyJet A320 at Gatwick EGKK by AeroPics, on Flickr
Back to some more charter traffic - Titan sent their all white 757:

G-POWH 'Titan Airways' B752 at Gatwick EGKK by AeroPics, on Flickr
And an incredibly long Thomas Cook Boeing 757-300:

G-JMAB Thomas Cook B753 at Gatwick EGKK by AeroPics, on Flickr
A less interesting TCX A321:

G-OMYJ Thomas Cook A321 at Gatwick EGKK by AeroPics, on Flickr
BAs 737s which have been repainted look very smart still as retirement looms:

G-DOCE British Airways B734 at Gatwick EGKK by AeroPics, on Flickr
And nice to see a Dove looking pristine, without any mismatched panels:

G-DBCB British Airways A319 at Gatwick EGKK by AeroPics, on Flickr
Thomson have a large presence at Gatwick. A 737 still wearing the perfectly good old livery:

G-TAWH Thomson B738 at Gatwick EGKK by AeroPics, on Flickr
And a couple in the new livery:

G-TAWK Thomson B738 at Gatwick EGKK by AeroPics, on Flickr

G-OOBB Thomson B752 at Gatwick EGKK by AeroPics, on Flickr
Flybe was another motivation for my trip, as they will shortly almost completely pullout of Gatwick as part of their restructuring:

G-ECOE Flybe DH8D at Gatwick EGKK by AeroPics, on Flickr

G-FBJI Flybe E175 at Gatwick EGKK by AeroPics, on Flickr
And a nice surprise was the eco livery Dash 8:

G-JEDP Flybe DH8D at Gatwick EGKK by AeroPics, on Flickr
Virgin made a single appearance in the middle of the day:

G-VGAL Virgin Atlantic B744 291213 EGKK by AeroPics, on Flickr
Norwegian Air Shuttle were responsible for a few movements:

LN-DJN Norwegian Air Shuttle B738 at Gatwick EGKK by AeroPics, on Flickr

LN-NOW Norweigian Air Shuttle B738 at Gatwick EGKK by AeroPics, on Flickr
And to end, a Turkish 737 and a nice Air Arabia A320:

TC-JFM Turksih Airlines B738 at Gatwick EGKK by AeroPics, on Flickr

CN-NMF Air Arabia A320 at Gatwick EGKK by AeroPics, on Flickr
Thanks for looking, and I hope these were of interest.