Debs75 bringing the car will definitely work out cheaper than public transport - the buses are expensive over here. I would say that the beach might be the best thing if the weather is great when you are here - if you fancy trying water sports then head to Lake (next door to Sandown) and Wightwater which is great. (Drive from Sandown, through the lights en route to Shanklin and look for car park just past the YMCA - lots of steps down to the beach.)
Anyone here for the Bank holiday will get to see the island full of scooters as thousands descend for the weekend. They are based in and around Ryde but do some fabulous ride outs and are pretty impressive.
The Garlic Festival this weekend is something that our girls really look forward to - especially the dancing dogs! We love the garlic sweetcorn and nosing though all the stalls and stands and watching the arena shows as well as seeing what bands are playing. We will be there on Sunday.
Robin Hill is the sister site to Blackgang Chine - you can get a ticket that covers one or both and return as often as you like in the week. Yes, taking your own food makes sense but it is pretty standard fare/park prices.
Yes, Puckpool Park is great but parking does fill up quickly - you can park at Ryde (big free car park right at the e nd of the seafront and walk along though.
Oh and if you are staying in Niton (lovely small village, very 1950s!!) then the Buddle Inn is lovely as is a walk over the fields to St Catherine's lighthouse.
(Waves to Charliepop! Both my girls are now patching again so are back in the gang with your DS - although they do not have sticky patches so cannot copy the bedroom door decoration which they loved at your house!)