To my knowledge, in most professional games, teams pick one offensive/damage dealing support and the other defensive/healing/saving support. To me, solo supports are those that can do both, have defensive and offensive spells.
Oracle comes to mind because I used to spam that hero when it was super strong. Ultimate is great to turn fights around and does actually save a good number of heroes provided you know what to follow it up with. His Q is OK, but needs a follow up stun from heroes that find it hard to land one like Lina, Leshrac Nyx. His Purifying Flames is the best, deals a huge amount of damage and heals to a great amount. Hero is nerfed right now but definitely not unplayable.
Phoenix is also good, but is really level dependant, almost as much as an offlaner. If you learn the hero a little, you'll realise how great it is. Good escape mechanism in Q that usually needs only 1 level. Fire spirits do great damage at higher levels, so does Sunray, which again, can be used both defensively and offensively. Probably my favourite hero to play right now.
Tusk is one of the harder ones, and is more successful in higher brackets than lower ones. You might think he's only an offensive damage dealing support, but his snowball is actually used to save heroes. It doesn't sound great because it's hard to pull off. You can go builds like Solar Crest and Blink or defensive like Mek and Force Staff.
There are more of course, Pudge, Shadow Demon, Wyvern, Warlock etc.
Witch Doctor
No support has good mobility inherently, some have high MS though (Skywrath, Pugna, KotL).
To my knowledge, in most professional games, teams pick one offensive/damage dealing support and the other defensive/healing/saving support. To me, solo supports are those that can do both, have defensive and offensive spells.
Oracle comes to mind because I used to spam that hero when it was super strong. Ultimate is great to turn fights around and does actually save a good number of heroes provided you know what to follow it up with. His Q is OK, but needs a follow up stun from heroes that find it hard to land one like Lina, Leshrac Nyx. His Purifying Flames is the best, deals a huge amount of damage and heals to a great amount. Hero is nerfed right now but definitely not unplayable.
Phoenix is also good, but is really level dependant, almost as much as an offlaner. If you learn the hero a little, you'll realise how great it is. Good escape mechanism in Q that usually needs only 1 level. Fire spirits do great damage at higher levels, so does Sunray, which again, can be used both defensively and offensively. Probably my favourite hero to play right now.
Tusk is one of the harder ones, and is more successful in higher brackets than lower ones. You might think he's only an offensive damage dealing support, but his snowball is actually used to save heroes. It doesn't sound great because it's hard to pull off. You can go builds like Solar Crest and Blink or defensive like Mek and Force Staff.
There are more of course, Pudge, Shadow Demon, Wyvern, Warlock etc.
Treant Protector
look at old vp- supports with big teamfight abilities that can afford to feed are the best.
treant, warlock dazzle come to mind