This a dream semi-final for any football fan and it's what the Champions League is all about. All I can say is sit back and enjoy.
I'm thrilled to be watching the game, but it's not so easy to try and call it because every time you find a positive for one side, you can find similar ones for the other!
Barcelona have been the best side in Europe for several years, but Bayern Munich are the new pretenders to that crown. They surprised many people when they beat Real Madrid in the semi-finals last year and they'll be looking to do the same to Barcelona this time around.
They've a great chance as well. I wrote in this column at the start of the season that Bayern Munich were my tip to win the competition because of their strength in depth and the way they have progressed over the last few years.
They have the best goalkeeper in the land in Manuel Neuer and people like Franck Ribery and Arjen Robben give you all sorts of threat. However, you'd have to say Bastian Schweinsteiger is their talisman in the middle of the park.
Going forward it's a shame that Toni Kroos is injured because he's a player I've been looking at for many years and Mario Mandzukic is banned, so you'd have to say the main goal threat is likely to come from Mario Gomez and Thomas Muller. They may have long periods of domination but will they have someone to score the vital goal when required? That's a big question going into the game.
Bayern have momentum on their side at this stage, though. The only blemish on their Champions League record this year is the second leg against Arsenal when they went asleep a little bit and lost 2-0 at home, but they came through the tie comfortably overall.
And we saw what they could do when they were revved up with their impressive performance against Juventus in the last eight, but if Barcelona turn up on the day and put on a performance then who am I to say that anybody can stop them?
They changed manager at the start of the season and he has had health issues during the season and overall they haven't been as fluent as in previous years. But when the chips are down this team is capable of beating anybody.
We saw that when they looked to be in big trouble against AC Milan when they lost 2-0, but upped it in the second leg and turned it all around.
Personally, I think they would be happy with a draw and take Bayern back to the Nou Camp and I think they may play more defensively than they would normally. You could even see Lionel Messi playing a little bit more withdrawn in this game.
They have drawn three of their last five Champions League games and Bayern would be concerned if they were to get another on Tuesday night because that would set the Spanish team up for a famous night the following week.
Bayern Munich need to win this first leg. They need the benefit of an advantage to take away with them. It should be a fantastic game and I'm edging towards them doing that. I still see them getting to the final.
NIALL'S PREDICTION: Bayern to narrowly win the first leg
See extended highlights of the first leg of Bayern Munich v Barcelona from midnight on Tuesday night (Wednesday morning) on Sky Sports 1 HD.Click here to read Niall's verdict on Borussia Dortmund v Real Madrid