You mention and on-board charger which I think is an absolute must not and extra. Beyond that I'd be sure to have a water temperature gauge that measures in 10ths, i.e. 49.5.

Going from a transom mount trolling motor to a bow mount foot control one.Big improvement in boat control.

Well, it could be the ladder I installed on the stern, or the new carpeting, or the Hotfoot, or the column mounted tilt/trim, or the on-board charger, or the Minn Kota Terrova with iPilot, or the burglar alarm, or the LED's that come on when a hatch is opened or the motorized trailer dolly.  I think what I like the best is the trailer dolly.

There's a few things I can't do without.   If I had to pick one item, it would be the Hotfoot.  I'll never own a boat without one.

good electronics a fast trolling motor and a recessed tray for my foot pedal. Theses are the things I have added to my boat since June.

My Humminbird SI unit...absolutely love it.

XM Radio.

A Few Good Friends.

A wide mouth thermos to keep boiling hot dogs in.

A Hot Foot.

A big plastic container in the storage locker with an extra change of clothes, rain gear, gloves, foot warmers etc.

First Aid Kit.

Lots of Snacks.

The Wife on occasion if she's been Good!

Just got my first boat about 8 months ago so more to come on this topic for me...I am buying a HB 798 this weekend and that will likely be my first true 'addition' - we will see how that goes - I am hopeful.

But at this point I will say that what I miss the most when I fish if I forget it, is my nail trimmers - I attach a small pair to an ID badge holder that has one of those pull strings on it so I just grab it, use it, and let go....I know, thats nothing big, but without it, I hate to go and pick up something else when changing out lures.

Also my cooler is essential - not only to keep my foods stored away - but also for another reason - I too fish both sides of my boat and my cooler sits in the middle and it acts as a bridge when going from one side to the other - also this sounds weird I am sure too, but that lower area is always cluttered with stuff and this way I just walk above it all.

Lowrance HDS8.  It's absolutely amazing...

New electronics.

More lures that I really didn't need....but who doesn't love having lures.

Having two daughters that absolutely love fishing with me.  Catching fish is just a bonus.

Now I just need to find a new boat to use on the lake so I have a little more room in it.

I just realized that I forgot to mention by far the most important addition to my boat. VHF radio. It has saved my butt twice after breakdowns on the water. I just tuned channel 16, keyed the mike and asked for help, and Vessel Assist was there both times within 15 minutes to tow me back to the ramp. I'd never go on the water without VHF radio again!!!

better electronics

Upgraded to a MK 24v trolling motor and my eagle 320 and 642c fishfinders. Also added some diamond plate to my trailer that keeps my feet dry when loading my boat.