As has been said many times before there's no such thing as unlimited, hosting providers will always impose limits on you.
I would look at how much storage you currently require then start to look at hosting plans, also many hosting provider do not allow storage to be used as file storage, files uploaded must be part of your site, anything more is considered data warehousing.
You can always use a solution such as Google Drive for serving files and images linked on your site.
You can find some Unlimited hosting and reseller offers. What do you need reseller account or just hosting?
I don't wanna talk about limits of unlimited, but I will ask you what do you exactly expect.
Do you need hosting with cPanel or custom hosting panel, do you need reseller account with unlimited cPanel accounts and space ore just unlimited space?
Unlimited Disk space and bandwidth does not occurs since 2013 in reseller hosting anymore. Since that alot of users/members and news says that unlimited does not occurs is the thing that most companies offer disks higher as 100GB like me.
I know of some providers who claim to offer "unlimited diskspace", but their customers have switched to us because they had issues with slow performance, the customers didn't even need so-called "unlimited diskspace". If you truely need diskspace that is not included with realistic Web/Reseller/VPS plans, then you'd be best off getting your own Dedicated Server.
As other members have mentioned, providers claiming to offer "unlimited diskspace" usually have many other hidden restrictions that prevent you from being able to use lots of diskspace, by them restricting things like, inodes, bandwidth speeds, etc.
it is true that you cannot find anything unlimited, specially disk space, which is expensive when you are gonna use a lot and then the owner will put restrictions on you, same goes with bandwidth, you cannot use all of them, also when they say unlimited bandwidth, they also said to use fair bandwidth or its suspended.
If your looking for unlimited hosting packages i would suggest looking very closely at the AUP/TOS (Acceptable use policy/terms of service)
I personally offer hosting package for 100GB for single sites and resellers for my highest package as this is mostly the max that a customer will hit depending on what they are hosting.
The word Unlimited means you have and Unlimited package in the cover but really they have you limited to like 10gb.
I have one customer that got booted from justhost cause he maxed out there I/O usage and he was on there unlimited package.
All im saying just be carefully of what they say behind the scenes.
As an unlimited host myself I think I speak for most of them by saying that such plans are not extended to your kind of hosting needs. For file and image hosting I recommend a vps/dedicated server or a host that specializes in that. Unlimited web hosting plans are for web sites suitable for a shared hosting environment, with emphasis on "web sites." Many limited hosts have the same restrictions.
Everyone must understand that there is no such thing as unlimited web hosting, it's not cost efficient, and no one wants a client that has 1-2 Tb of data and pays $5/month.If there weren't any limits, hosting companies would lose money, not to mention run out of space. I advise you to avoid providers claiming to offer unlimited disk space and bandwidth or read the ToS a couple of times.
I worked for several hosting companies, and no one cared about a website under 20 GB, people looking for unlimited disk space are generally not trying to host 2-3 Gb websites, there is no reason to look for unlimited packafes in this case.
I've seen Moodle installs with over 800 Gb, photographer websites which stored client files 600Gb+, websites that stored legit mp3 audio files 700Gb and yes these websites were working just fine on a shared server.
Many web hosts proclaim to offer unlimited disk space in Reseller hosting, but everything has a cost associated with it. Many of unlimited offer in webhosting may have conditions. Thus better to know all the terms and conditions before signing up hosting plan.
Well, Most of the company offered Unlimited disk on Reseller plans but that doesn't mean you can use that for warez, you can simply ask them before you buy reseller from them and you just need to check out the terms of service on their website. If you really need space for hosting files and images, I would suggest you go with VPS plan instead of reseller plan. Because on VPS plans you will not have any restrictions at all. Just for your knowledge Nothing is Unlimited because there is always a limit to anything like most of the hosting company use around 2tb space on their servers and they provide unlimited fair use to the customer which means people can only use that unlimited space for only fair use not for uploading many files etc. VPS are recommended for such purpose.
With limits you will at lest claim that you purchase 200GB disk but with Unlimited plan, If they will suspend your account at just 25GB usage then none of people will support you in any forum and they will advice you to never chose unlimited plans.
If you have big space requirements shared hosting is not for you and that includes website, reseller and VPS. For big storage solutions the best option is always a dedicated server with HDD drives budget wise and SSD performance wise.
Though I haven't tested them but hard about them.
My recommendation is don't go with unlimited hosting, try to find limited reseller with high volume of hard disk.Unlimited hosts servers are sometimes over crowded.