Lallana, a unique talent. That's stretching it a bit. Ask a hundred fans from all over the country to name players who are an unique talent. Don't think many would name Lallana. Hunt, Rush, Hughes, Kenny, Keegan, Barnes, Fowler, Owen, Suarez, Torrez, Sami, Gerrard etc from yesteryear and only Coutinho from the present team for me. Lallana is a good player but not special yet, but will all have different standards
If we're being so strict with it, and not simply meaning a unique combination of skills, but that peculiar skills combo + world class application of said talents, I'd say only Dalglish, Keegan, Barnes, Suarez and Gerrard would truly qualify, with Suarez probably being the ultimate attacking example (insane touch and technique + insane reading and anticipation + insane hunger and workrate = an extremely rare force of nature), and Gerrard the ideal all-round complete footballer example, who you could plonk anywhere outfield at the height of his abilities and he would do more than just a job for you - not flawless as a player, but incredibly rare nonetheless (nevermind that he's a born & bred Liverpudlian as well!).
Rush and Fowler were easily the most natural finishers we've ever seen here, but they come from quite a long line of instinctive goalpoachers (a type of striker which is actually dying out now in the modern game); Owen maybe has a decent shout through him being just so tiny and explosive, it had such a massive impact and afterwards you began seeing way more slight little whippet players in his mould, pace right off the blocks and acceleration being everything. But with that in mind, I'm not sure he was uniquely talented - arguably the most effective of his kind in his prime, but not quite a one-off. All of Rush, Fowler and Owen are in a pool that includes Greaves, Muller and Romario, who were pretty fucking good at what they specialised in.
Keegan was a brilliantly talented but also brilliantly enthusiastic and hardworking forward, so I do think he'd qualify. Kenny was just so clever, it's not so much touch and technique (not too shabby!) but spatial awareness, reading of play, skill with back to goal, etc. - he's defo a pretty unusual and near-perfected type of attacking player, both in his time and now (maybe more now). Barnes was culturally a very significant new occurence (world class black 'English' footy superstar, and occasional rapper), but purely as a footballer had a pretty unstoppable mix of physical and technical strengths, plus plenty of imagination and adaptability, as proved later in his career when his legs had gone.
I think Lallana is just so silky and hardworking at the same time, running full pelt all game, he suits Klopp down to the ground, arguably the most of all our players, along with Firmino, Coutinho, Mane and maybe Henderson (for his incredible stamina). He definitely has a unique skillset for an Englishman, no doubt.